Owing to time constraints, a fully-integrated PMDF MessageStore and popstore manual is not yet available. However, much of the documentation for the PMDF popstore applies to the PMDF MessageStore. This chapter supplements the PMDF popstore documentation with information specific to the PMDF MessageStore.

2.1 Introduction

Whereas, the popstore is a message store streamlined for use with POP3 clients, the PMDF MessageStore is a message store streamlined for use with IMAP clients, and, incidentally, also supports POP3 clients.

The MessageStore is primarily designed for IMAP scalability and manageability. It supports public folders so that a single mailing list subscription can be shared by a large community of users. Responses to common IMAP operations are pre-computed at delivery time, and the messages are stored in a ready-to-download format for IMAP without the need for any pre-processing of the message data. In order to simplify backup and restore of a single user, each user's mail is stored in a single directory subtree.

The major components of the MessageStore are described below.

MessageStore and popstore POP3 server

A new dual-store, multi-threaded POP server is provided on all platforms which supports both the popstore and MessageStore. This server includes security and performance enhancements not possible while maintaining support for legacy mailbox formats.

MessageStore IMAP server

A new multi-threaded IMAP server is provided to access the MessageStore. This server supports the IMAP4 ACL and QUOTA extensions so that existing clients can be used to directly manage shared folders and quotas through the IMAP protocol.

Poppassd server

A multi-threaded poppassd server for users of Eudora, Mulberry, and other clients which support the ad hoc poppassd protocol for changing passwords.

Web-based user interface

A basic web-based user interface is provided. This interface allows users to use a web-client to change their password as well as see basic usage information about their account. Unlike the user interface for the popstore, this interface does not allow MessageStore users to access mail stored for their account. For details, see Chapter 5.

Web-based management utility

A web-based management utility to manage the MessageStore. The utility presents itself as a multi-threaded CGI accessed through the PMDF HTTP server. MessageStore users with management privileges can use this interface to monitor and manage the MessageStore. This utility is extremely reconfigurable; the entire interface can be changed around to suit a site's needs. See Chapter 4 for a description of this interface.

Command line management utility

A command line oriented management utility. Users with operating system privileges as well as MessageStore users who have been granted MessageStore management privileges can use the utility. See Chapters 6 or 7 for information about this utility.

Migration utility

A utility is provided to migrate the mail inboxes for native login and popstore accounts to the MessageStore. The utility can create a MessageStore account for each migrated user, migrate their mail inbox, and then establish mail forwarding from their prior account's message store to the MessageStore. See Chapter 8 for details about this utility.

Forwarding database

A forwarding database which allows mail for MessageStore users, fictitious or otherwise, to be automatically redirected elsewhere. Consult Section 1.5 for further details.

Delivery channel

A master channel to deliver inbound messages to the MessageStore. Inbound messages for the MessageStore are queued to this channel by PMDF. The channel is then run by PMDF to deliver the messages to the MessageStore. See Section 10.1 for details.

Validating accounts

The immediate validation of accounts is turned on by default on the msgstore channel so that it can, when presented with a popstore address, immediately check to see if it is valid or not (e.g., is it a valid recipient address, is the recipient allowed to receive new messages, etc.). This allows the various incoming mail streams to reject up front invalid messages for the popstore thereby obviating cases where the message is received only to then have to be bounced. Section 10.1.1 contains additional information on this account validation.

API

The popstore API, while including full support for the popstore, provides some limited support for creating and deleting MessageStore accounts. See Section 2.6 below and Chapter 12 for further details.

Reconstruct utility

A utility is provided to reconstruct MessageStore index and mailbox list files in the event they are corrupted. In addition, if mailboxes are restored from backup, this utility can re-integrate them into the MessageStore without the need to stop the servers. For further information on this utility, see Section 2.5.4.