There are five servers which interact with the popstore and MessageStore: two POP3 servers, the MessageStore's IMAP server, the poppassd server, and the HTTP server. Each of these servers are documented in the PMDF System Manager's Guide.

11.1 POP3 Servers

On UNIX and OpenVMS platforms, a "legacy" multi-threaded POP3 server which serves out both native mailboxes as well as popstore mailboxes is provided. Specifically, on UNIX systems the legacy POP3 server serves out both popstore and BSD-style mailboxes. On OpenVMS systems the legacy server serves out both popstore and VMS MAIL mailboxes. When a client attempts to authenticate against the legacy POP3 server, the server first checks for a popstore account for the username. If there is a match, the associated popstore mailbox is served out. If there is no match, then the server checks for a native mailbox and serves it out if there is one. If you are not using the native mailbox feature, the non-legacy POP3 server should be used instead as it has better performance and security characteristics.

The "non-legacy" POP3 server is a multi-threaded server which is capable of serving out both popstore and MessageStore mailboxes. It cannot, however, serve out native mailboxes. This server has improved performance over the legacy POP3 server. In addition, this server is required to take advantage of the multiple domain facility of the popstore.

Both POP3 servers use PMDF's authentication services and as such supports plain text passwords as well as APOP, CRAM-MD5 and DIGEST-MD5 authentication. Additionally, the server supports SASL (RFC 2222). For further information on the POP3 server or authentication services, consult the "Connection Authentication and Password Management" chapter of the PMDF System Manager's Guide.