Synchronization of mailboxes of different types

Claims

The invention claimed is:

1. An apparatus for indicating in one of a first mailbox of a first electronic messaging system and a second mailbox of a second electronic messaging system a content and a state of a message stored in another of the first mailbox and the second mailbox, the first electronic messaging system for handling first messages and defining at least one first mailbox for storing the first messages, each first message having a first data structure containing information expressed in a first medium and having a first format, and each stored first message having one of a plurality of states, and the second electronic messaging system for handling second messages and defining at least one second mailbox for storing the second messages, each second message having a second data structure containing information expressed in a second medium and having a second format, at least one of the second data structure, the second medium, and the second format being different respectively from the first data structure, the first medium, and the first format, and each stored second message having one of the plurality of states, the apparatus comprising:

first means, cooperative with the first mailbox and the second mailbox and responsive to storing of a second message in the second mailbox, for retrieving at least some of the information from the second message, generating a corresponding first message forming a message pair with the second message and containing at least some of the information retrieved from the second message, storing the first message in the first mailbox, and also raising a partial-copy indication for the first message if the first message does not contain all of the information contained in the second message of the message pair;

second means, cooperative with the first mailbox and the second mailbox and responsive to a change in state of one of the stored messages of the message pair, for effecting a same said change in state of other of the stored messages of the message pair; and

third means, cooperative with the first mailbox and the second mailbox and responsive to deletion of one of the stored messages of the message pair from one of the mailboxes, for deleting other of the stored messages of the message pair from other of the mailboxes.

2. The apparatus of claim 1 further comprising:

fourth means, cooperative with the first mailbox and the second mailbox and responsive to storing of a first message in the first mailbox, for retrieving at least some of the information from the first message, generating a corresponding second message forming a message pair with the first message and containing at least some of the information retrieved from the first message, storing the second message in the second mailbox, and also raising a partial-copy indication for the second message if the second message does not contain all of the information contained in the first message of the message pair; wherein

the second means comprise

fifth means, cooperative with the first mailbox and the second mailbox and responsive to a change in state of the stored second message of the message pair, for effecting a same said change in state of the stored first message of the message pair, and

sixth means, cooperative with the first mailbox and the second mailbox and responsive to a change in state of the stored second message of a message pair, for effecting a same said change in state of the stored first message of the message pair; and wherein

the third means comprise

seventh means, cooperative with the first mailbox and the second mailbox and responsive to deletion of the stored second message of the message pair from the second mailbox, for deleting the stored first message of the message pair from the first mailbox, and

eighth means, cooperative with the first mailbox and the second mailbox and responsive to deletion of the stored first message of the message pair from the first mailbox, for deleting the stored second message of the message pair from the second mailbox.

3. The apparatus of claim 2 wherein:

the apparatus includes a data record for each message pair, the data record holding data that indicate an identifier of the first message of the message pair, an identifier of the second message of the message pair, the state of the first message of the message pair, the state of the second message of the message pair, which one of the first and the second electronic messaging systems is a native system of the message pair, and whether the corresponding one of the messages of the message pair is a full copy or a partial copy of the other of the messages of the message pair.

4. The apparatus of claim 2 wherein:

the plurality of states are a sequence of the plurality of states; and

the fifth means comprise

ninth means, cooperative with the first mailbox and the second mailbox and responsive to a sequential change in state of the stored second message of any message pair, for effecting same said change in state of the stored first message of said any message pair, and

tenth means, cooperative with the seventh means and the ninth means and responsive to a non-sequential change in the state of the stored second message of an individual message pair, for causing the ninth means to cease being responsive to changes in the state of the stored second message of the individual message pair and for causing the seventh means to cease being responsive to the deletion of the stored second message of the individual message pair from the second mailbox, whereby the apparatus ceases to perform said indicating for the individual message pair.

5. The apparatus of claim 4 wherein:

the sixth means comprise

eleventh means, cooperative with the first mailbox and the second mailbox and responsive to a sequential change in state of the stored first message of any message pair, for effecting same said change in state of the stored second message of said any message pair, and

twelfth means, cooperative with the eighth means and the eleventh means and responsive to a non-sequential change in the state of the stored first message of an individual message pair, for causing the eleventh means to cease being responsive to changes in the state of the stored first message of the individual message pair and for causing the eighth means to cease being responsive to the deletion of the stored first message of the individual message pair from the first mailbox, whereby the apparatus ceases to perform said indicating for the individual message pair.

6. The apparatus of claim 5 wherein:

the apparatus includes a data record for each message pair, the data record holding data that indicate an identifier of the first message of the message pair, an identifier of the second message of the message pair, the state of the first message of the message pair, the state of the second message of the message pair, which one of the first and the second electronic messaging systems is a native system of the message pair, whether the corresponding one of the messages of the message pair is a full copy or a partial copy of the other of the messages of the message pair, and whether said indicating is being performed for the message pair.

7. The apparatus of claim 6 wherein:

the ninth means include

thirteenth means, cooperative with the first mailbox and the second mailbox and responsive to a change in state of the stored second message of an individual message pair to a state other than an expired state, for effecting a same said change in the state of the stored first message of the message pair, and

fourteenth means, cooperative with the seventh means and the ninth means and responsive to a change in state of the stored second message of the individual message pair to the expired state, for causing the ninth means to cease being responsive to changes in the state of the stored second message of the individual message pair and for causing the seventh means to cease being responsive to the deletion of the stored second message of the individual message pair from the second mailbox, whereby the apparatus ceases to perform said indicating for the individual message pair.

8. The apparatus of claim 7 wherein:

the first messaging system is an e-mail system and the second messaging system is a voice-mail system.

9. The apparatus of claim 6 wherein:

the ninth means include

thirteenth means, cooperative with the first mailbox and the second mailbox and responsive to a change in state of the stored second message, of an individual message pair whose data record indicates that the second messaging system is the native system, to a state other than an expired state, for effecting a same said change in the state of the first message of the message pair, and

fourteenth means, cooperative with the seventh means and the ninth means and responsive to a change in state of the stored second message of the individual message pair to the expired state, for causing the ninth means to cease being responsive to changes in the state of the stored second message of the individual message pair and for causing the seventh means to cease being responsive to the deletion of the stored second message of the individual message pair from the second mailbox, whereby the apparatus ceases to perform said indicating for the individual message pair.

10. The apparatus of claim 1 wherein:

the second means include

fourth means, cooperative with the first mailbox and the second mailbox and responsive to a change in state of the stored second message of an individual message pair to a state other than an expired state, for effecting a same said change in the state of the stored first message of the message pair, and

fifth means, cooperative with the third means and the fourth means and responsive to a change in state of the stored second message of the individual message pair to the expired state, for causing the fourth means to cease being responsive to changes in the state of the stored second message of the individual message pair and for causing the third means to cease being responsive to deletion of the stored second message of the individual message pair from the second mailbox, whereby the apparatus ceases to perform said indicating for the individual message pair.

11. The apparatus of claim 1 wherein:

one of the first and the second messaging systems is an e-mail system and another of the first and the second messaging systems is a voice-mail system.

12. The apparatus of claim 1 wherein:

the first means include

means, cooperative with the first mailbox and the second mailbox and responsive to storing of a second message that is marked as private in the second mailbox, for retrieving only header information from the second message, generating a corresponding first message forming a message pair with the second message and containing only the header information from the second message, storing the first message in the first mailbox, and raising the partial-copy indication for the first message.

13. The apparatus of claim 1 wherein:

the first means include

means, cooperative with the first mailbox and the second mailbox and responsive to storing of a second message containing information that is encrypted in the second mailbox, for retrieving at least any non-encrypted information from the second message, generating a corresponding first message forming a message pair with the second message and containing only said any non-encrypted information retrieved from the second message, storing the first message in the first mailbox, and raising the partial-copy indication for the first message.

14. The apparatus of claim 1 wherein:

the second message comprises a message header and a message body; and

the first means include

fourth means, cooperative with the first mailbox and the second mailbox and responsive to storing of the second message in the second mailbox, for determining whether the first mailbox is to be synchronized partially or fully with the second mailbox, and

fifth means, cooperative with the first mailbox and the second mailbox and the fourth means and, responsive to a determination by the fourth means that the first mailbox is to be synchronized partially with the second mailbox, for retrieving the message header and not retrieving the message body of the second message, generating from the retrieved message header the corresponding first message comprising a message header and not comprising a message body, storing generated corresponding first message in the first mailbox, and also raising the partial-copy indication for the first message, and further responsive to a determination by the fourth means that the first mailbox is to be synchronized fully with the second mailbox, for retrieving the message header and at least some of the message body of the second message generating from the retrieved message header and the at least some of the message body of the second message the corresponding first message comprising a message header and a message body, storing the generated corresponding first message in the first mailbox, and also raising the partial-copy indication for the first message if the first message does not contain all of the message body of the second message.

15. The apparatus of claim 1 wherein:

each first message has a first data structure containing at least one first data object of information, each first data object being expressed in one of a plurality of first media and having one of a plurality of first formats,

each second message has a second data structure containing at least one second data object of information, each second data object being expressed in one of a plurality of second media and having one of a plurality of second formats, at least one of the plurality of second media and the plurality of second formats being different respectively from the plurality of first media and the first formats, and

the first means include

means, cooperative with the first mailbox and the second mailbox and responsive to storing of a second message in the second mailbox that contains an individual first data object expressed in an individual second medium and having an individual second format which cannot be converted by the synchronizer into a first data object expressed in a first medium and having a first format, for retrieving from the second message at least second data objects other than the individual data object, generating a corresponding first message forming a message pair with the second message and containing first data objects by converting the second medium and the second format of each retrieved second data object other than the individual second data object into a first medium and a first format of a first data object, storing the first message in the first mailbox, and raising the partial-copy indication for the first message.

16. An apparatus comprising:

a first electronic messaging system for handling first messages and defining at least one first mailbox for storing the first messages, each first message having a first data structure containing information expressed in a first medium and having a first format, and each stored first message having one of a plurality of states;

a second electronic messaging system for handling second messages and defining at least one second mailbox for storing the second messages, each second message having a second data structure containing information expressed in a second medium and having a second format, at least one of the second data structure, the second medium, and the second format being different respectively from the first data structure, the first medium, and the first format, and each stored second message having one of the plurality of states; and

means for indicating in one of a first mailbox of the first messaging system and a second mailbox of the second messaging system a content and a state of a message stored in another of the first mailbox and the second mailbox, including

first means, cooperative with the first mailbox and the second mailbox and responsive to storing of a second message in the second mailbox, for retrieving at least some of the information from the second message, generating a corresponding first message forming a message pair with the second message and containing at least some of the information retrieved from the second message, storing the first message in the first mailbox, and also raising a partial-copy indication for the first message if the first message does not contain all of the information contained in the second message of the message pair,

second means, cooperative with the first mailbox and the second mailbox and responsive to a change in state of one of the stored messages of the message pair, for effecting a same said change in state of other of the stored messages of the message pair, and

third means, cooperative with the first mailbox and the second mailbox and responsive to deletion of one of the stored messages of the message pair from one of the mailboxes, for deleting other of the stored messages of the message pair from other of the mailboxes.

17. The apparatus of claim 16 wherein:

the means for indicating further comprise

fourth means, cooperative with the first mailbox and the second mailbox and responsive to storing of a first message in the first mailbox, for retrieving at least some of the information from the first message, generating a corresponding second message forming a message pair with the first message and containing at least some of the information retrieved from the first message, storing the second message in the second mailbox, and also raising a partial-copy indication for the second message if the second message does not contain all of the information contained in the first message of the message pair; wherein

the second means comprise

fifth means, cooperative with the first mailbox and the second mailbox and responsive to a change in state of the stored second message of the message pair, for effecting a same said change in state of the stored first message of the message pair, and

sixth means, cooperative with the first mailbox and the second mailbox and responsive to a change in state of the stored second message of a message pair, for effecting a same said change in state of the stored first message of the message pair; and wherein

the third means comprise

seventh means, cooperative with the first mailbox and the second mailbox and responsive to deletion of the stored second message of the message pair from the second mailbox, for deleting the stored first message of the message pair from the first mailbox, and

eighth means, cooperative with the first mailbox and the second mailbox and responsive to deletion of the stored first message of the message pair from the first mailbox, for deleting the stored second message of the message pair from the second mailbox.

18. A method of indicating in one of a first mailbox of a first electronic messaging system and a second mailbox of a second electronic messaging system a content and a state of a message stored in another of the first mailbox and the second mailbox, the first electronic messaging system for handling first messages and defining at least one first mailbox for storing the first messages, each first message having a first data structure containing information expressed in a first medium and having a first format, and each stored first message having one of a plurality of states, and the second electronic messaging system for handling second messages and defining at least one second mailbox for storing the second messages, each second message having a second data structure containing information expressed in a second medium and having a second format, at least one of the second data structure, the second medium, and the second format being different respectively from the first data structure, the first medium, and the first format, and each stored second message having one of the plurality of states, the method comprising the steps of:

in response to storing of a second message in the second mailbox, retrieving at least some of the information from the second message;

generating a corresponding first message forming a message pair with the second message and containing at least some of the information retrieved from the second message;

storing the first message in the first mailbox;

raising a partial-copy indication for the first message, if the first message does not contain all of the information contained in the second message of the message pair;

in response to a change in state of one of the stored messages of the message pair, effecting a same said change in state of other of the stored messages of the message pair; and

in response to deletion of one of the stored messages of the message pair from one of the mailboxes, deleting other of the stored messages of the message pair from other of the mailboxes.

19. The method of claim 18 further comprising the steps of

in response to storing of a first message in the first mailbox, retrieving at least some of the information from the first message,

generating a corresponding second message forming a message pair with the first message and containing at least some of the information retrieved from the first message,

storing the second message in the second mailbox, and

raising a partial-copy indication for the second message, if the second message does not contain all of the information contained in the first message of the message pair; wherein

the step of effecting comprises the steps of

in response to a change in state of the stored second message of the message pair, effecting a same said change in state of a stored said first message of the message pair, and

in response to a change in state of the stored first message of a message pair, effecting a same said change in state of a stored said second message of the message pair; and wherein

the step of deleting comprises the steps of

in response to deletion of the stored second message of the message pair from the second mailbox, deleting a stored said first message of the message pair from the first mailbox, and

in response to deletion of the stored first message of a message pair from the first mailbox, deleting a stored said second message of the message pair from the second mailbox.

TECHNICAL FIELD

This invention relates to electronic messaging systems.

BACKGROUND OF THE INVENTION

Various types of electronic messaging systems are known in the art. They include single-medium systems such as e-mail systems and voice mail systems, as well as multi-media messaging systems, such as the AT&T Intuity.RTM. messaging system, that handle messages having any combination of voice, fax, text, and data components. Mostly, these various types of systems are incompatible with each other. For example, they use different kinds of telecommunications networks--telephone network, data LANs, the Internet--for message transport. They use different kinds of terminals--data terminals, telephones, fax machines, multimedia workstations--for message creation and retrieval. They handle different types of media--voice, data, still image, video, plain (ASCII) text, enriched text, etc. They use different kinds of objects--binary data files, compressed digitized audio files, bit map image files, graphics files, compressed digitized image files--for message representation. They use different addressing schemes--data network login IDs, telephone numbers, Internet addresses. And even messaging systems that handle the messages of the same media represented in the same objects and addressed via the same address type are often incompatible because of differences in message structure or in formats of the same kinds of objects. Hence, interoperability--the exchange of messages--between the various messaging systems is often impossible.

As a consequence, a user wishing to exchange messages with various sources or destinations must often employ a plurality of messaging systems, and individually monitor the status of all of them.

To avoid imposing this burden on users, various schemes have been proposed for informing the users in a unified manner of the arrival of messages in any of a plurality of messaging systems, and for enabling the users to retrieve messages from a plurality of messaging systems through one of those messaging systems. Illustrative examples of such schemes are described in U.S. Pat. Nos. 4,837,798, 4,476,349, 4,646,346, and 4,612,416.

Schemes that merely rely upon informing the users in a unified manner of the arrival of messages in any of a plurality of messaging systems only address the problem of a user having to monitor a plurality of systems for message arrival; they do nothing to ease the user's need to access a plurality of the systems. Moreover, these schemes have not been broadly endorsed, because the notifications can become more troublesome than effective. For example, one known implementation of integrated notification of e-mail and voice mail messages created two notifications for each received message, one notification for each system. These notifications had to be dealt with independently. They were not directly tied to the messages, and as a consequence, a user could first see a notification in system A, then go to system B to retrieve the message, and become confused as to whether the message being retrieved was the one which created the notifications or a newly-arrived message which might also have created a latent notification that would be encountered at some time in the future in messaging system A.

Schemes that enable users to retrieve messages from a plurality of messaging systems through others of those messaging systems typically rely upon translation of the messages from the media, objects, and/or formats of the native messaging system into the media, objects, and/or formats of the messaging system or systems through which the messages will be retrieved. An illustrative example of such a translation scheme is disclosed in U.S. patent application Ser. No. 08/029193 to R. M. Klein entitled "Multi-Media Integrated Message Arrangement", filed on Mar. 10, 1993, issued on Dec. 26, 1995, as U.S. Pat. No. 5,479,411, and assigned to the same assignee as this application. Unfortunately, all media, objects, and/or formats are not fully convertible into all other media, objects, and/or formats. Unconstrained "morphing" without loss of fidelity or information is technically infeasible at this time. For example, it is presently not feasible to convert a video object into an audio object, or vice versa, without a significant loss of information. Nor is it forseen to become feasible in the future. The reason is that this type of morphing is more a question of interpretation than of conversion, and depends on human perceptions and human experience that machines cannot duplicate.

While it is relatively easy to understand why this cannot always work, it is more difficult to determine when it might work acceptably well. For example, text-to-speech conversion is now to the point where pronunciation errors are minimal, so that it can be effectively used as an audio method of accessing text information. Also, optical character recognition can convert text-only faxes to text with very high accuracy. Despite the character recognition errors and the mechanized voice pronunciation errors, enough information is conveyed to make the message understandable. So as technology advances, morphing may become more acceptable as an information-access method. But it is highly unlikely that it will ever become as effective as, and hence that it will fully replace, the ability to access messages in their native form.

An emerging approach to this problem is to provide integration at the user interface for messages being retained in more than one messaging system. The problem here is that each user interface must be enhanced to deal with the peculiarities of the various messaging systems. This often results in a confusing user interface where the operations involved in managing a message are dependent upon which messaging system "owns" (i.e., is the native system of) the message. Another problem may arise when a user moves messages out of the native messaging server, which thereby precludes the server from performing its intended services with respect to those messages.

SUMMARY OF THE INVENTION

This invention is directed to solving these and other problems and disadvantages of the art. Generally according to the invention, the contents of a pair of mailboxes, each one of which resides in a different electronic messaging system, are automatically synchronized both in message content and in message state. Illustratively, one messaging system may be an e-mail system and the other messaging system may be a voice-mail system. The synchronization enables the mailbox user/owner to depend on either system to notify him or her of arrival of any messages in both systems. The user may retrieve all messages from either system and do so in an identical manner for all messages, or may retrieve some messages from the one system and other messages from the other system irrespective of which system the messages originated on. The user may also determine the correct status of all messages from examining either system. Synchronization is effected in part by automatically creating a corresponding message in the mailbox in the one system for every message that arrives in the mailbox in the other system. If the corresponding message does not contain all of the information of the original message--for example, because some information in the original message is expressed in a medium or has a format that is incompatible with the other system--a partial-copy indication is raised for the corresponding message. This alerts the user who accesses the corresponding message in the one system to the fact that he or she must access the original message in the message's native system in order to obtain all message information. This feature allows synchronization of mailboxes on different types of messaging systems that are incompatible, or cannot be made compatible by message structure, media, and format conversions, with each other. It also allows a user to select the degree of synchronization--for example, to synchronize message headers only. Optionally, the synchronization may be conducted only in one direction, wherein contents of the one mailbox are synchronized with the contents of the other mailbox but not vice versa. This avoids synchronization processing that may be superfluous if the user exclusively or predominantly accesses the one mailbox and not the other.

Specifically according to the invention, there is provided a synchronizer for synchronizing a first mailbox of a first electronic messaging system with a second mailbox of a second electronic messaging system, the first electronic messaging system for handling first messages and defining at least one first mailbox for storing the first messages, each first message having a first data structure containing information expressed in a first medium and having a first format, and each stored first message having one of a plurality of states, and the second electronic messaging system for handling second messages and defining at least one second mailbox for storing the second messages, each second message having a second data structure containing information expressed in a second medium and having a second format, at least one of the second data structure, the second medium, and the second format being different respectively from the first data structure, the first medium, and the first format, and each stored second message having one of the plurality of states. The synchronizer comprises means responsive to storing of a second message in the second mailbox, for retrieving at least some of the information from the second message, generating a corresponding first message forming a message pair with the second message and containing at least some of the information retrieved from the second message, storing the first message in the first mailbox, and also raising a partial-copy indication for the first message if the first message does not contain all of the information contained in the second message of the message pair. The synchronizer also comprises means responsive to a change in state of one stored message of a message pair, for effecting a same said change in state of the other stored message of the message pair. The synchronizer furthermore comprises means responsive to deletion of one stored message of a message pair from one of the mailboxes, for deleting the other stored message of the message pair from the other mailbox. Alternatively, state changes and/or message deletions may be conducted in only one direction.

Preferably, the synchronization is fully bidirectional, and the synchronizer further comprises means responsive to storing of a first message in the first mailbox, for retrieving at least some of the information from the first message, generating a corresponding second message forming a message pair with the first message and containing at least some of the information retrieved from the first message, storing the second message in the second mailbox, and also raising a partial-copy indication for the second message if the second message does not contain all of the information contained in the first message of the message pair. Further preferably, the synchronization between the two messages of a message pair may be "broken" or unlinked. This allows messages in one mailbox to enter states or to undergo state transitions that are incompatible with the other mailbox.

In addition to the synchronizer, an apparatus comprising the synchronizer and the two messaging systems, and a synchronization method comprising the functionality of the synchronizer, are also claimed.

These and other advantages and features of the invention will become more apparent from the following description of an illustrative embodiment of the invention taken together with the drawing.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram of a telecommunications system which includes an illustrative embodiment of the invention;

FIG. 2 is a block diagram of a data structure of the synchronizer of the system of FIG. 1;

FIGS. 3-7 are a flow diagram of a message-state synchronization function of the synchronizer of the system of FIG. 1;

FIGS. 8-13 are a flow diagram of a message-creation function of the synchronizer of the systems of FIG. 1 for creating an e-mail system message from a voice-mail system message;

FIGS. 14-18 are a flow diagram of a message-creation function of the synchronizer of the system of FIG. 1 for creating a voice-mail system message from an e-mail system message;

FIG. 19 is a block diagram of a first generalized e-mail system message;

FIG. 20 is a block diagram of a second generalized e-mail system message; and

FIG. 21 is a block diagram of a generalized voice-mail system message.

DETAILED DESCRIPTION

FIG. 1 shows a telecommunications system that comprises a plurality of interconnected messaging systems: a conventional e-mail system 29 and a conventional voice-mail system 39. While for illustrative purposes only two different messaging systems are shown, the telecommunications system of FIG. 1 may comprise any number of any types of messaging systems. As is conventional, the e-mail system 29 includes an e-mail server 20, such as a host processor, that serves a plurality of e-mail user terminals 26, such as personal computers. User terminals 26 may be connected to e-mail server 20 directly, or indirectly by an email network 25, such as a LAN, a WAN, or some other data transport network. E-mail network 25 also connects e-mail server 20 to other e-mail servers of the e-mail system 29. E-mail server 20 implements a plurality of e-mail mailboxes 21-22 for receiving and storing e-mail messages 23-24 for subscribers of the e-mail system 29. Illustratively, the e-mail system 29 is the Lotus Notes system.

As is conventional, the voice-mail system 39 includes a voice-mail server 30, such as an AT&T Intuity.RTM. messaging system. In actuality, the Intuity messaging system is a multi-media system that is presently capable of accommodating separate or integrated audio, fax, text, and data messages. But to simplify this illustration, only the audio capability of the Intuity messaging system will be considered here in any detail. Voice-mail server 30 serves a plurality of voice-mail terminals 36, such as telephones. Although voice-mail terminals 36 may be connected to voice-mail server 30 directly, typically they are connected to the voice-mail server 30 by means of a voice-mail network 35, such as the telephone network. Voice-mail network 35 also connects voice-mail server 30 to other voice-mail servers of the voice-mail system 39. Voice-mail server 30 implements a plurality of voice-mail mailboxes 31-32 for receiving and storing audio messages 33-34 for subscribers of the voice-mail system 39.

According to the invention, the e-mail system 29 and the voice-mail system 39 are interconnected by a synchronizer 10. Synchronizer 10 is illustratively implemented by a suitably-programmed general-purpose computer. Synchronizer 10 has an e-mail interface 11 for communicating with e-mail server 20 by means of a communications protocol that is understood by e-mail server 20, such as a version of the standard ("common messaging calls") CMC protocol put forth by an X.400 subcommittee of the XAPIA industry committee. Synchronizer 10 also has a voice-mail interface 13 for communicating with voice-mail server 30 by means of a communications protocol that is understood by voice-mail server 30. In the case of the voice-mail server 30 being the Intuity messaging system, the protocol is preferably version 4 of the Intuity Messaging Application Programmer's Interface (IMAPI) protocol. Synchronizer 10 further includes a memory 14 for storing data and programs, and a processor 12 which executes the programs and uses the data that are stored in memory 14. Alternatively, synchronizer 10 may be implemented on e-mail server 20 or on voice-mail server 30.

Memory 14 of synchronizer 10 includes a plurality of mailbox-pair state tables 200-201, as shown in FIG. 2. There is one table 200-201 per mailbox pair. A mailbox pair is a pair of mailboxes, one in each of the systems 29, 39 whose contents are to be synchronized, and that may or may not belong to the same user. For example, if mailbox 21 in e-mail system 29 and mailbox 31 in voice-mail system 39 belong to the same user, then the mailboxes 21 and 31 form a mailbox pair. Illustratively, mailbox-pair state table 200 in FIG. 2