The Post Office Protocol (POP) server is the iSeries™ implementation of the Post Office Protocol Version 3 mail interface.
It provides electronic mailboxes on the iSeries server from which clients can retrieve mail. Any mail client that supports the POP3 protocol can use this server, such as Netscape Mail, Outlook Express, or Eudora. Clients might be running on any platform, such as Windows®, OS/2®, AIX®, or Macintosh.
The POP server serves as a temporary holding area for mail until it is retrieved by the mail client. When the mail client connects to the server, it queries the contents of its mailbox to see if there is any mail to retrieve. If there is, it retrieves the mail one message at a time. After a message has been retrieved, the client instructs the server to mark that message for deletion when the client session is complete. The client retrieves all of the messages in the mailbox and then issues a command that tells the server to delete all of the messages that are marked for deletion and to disconnect from the client.
POP mail clients use verbs to communicate with the POP server. Verbs supported by the iSeries POP server are described in POP protocol.
For more information about the POP protocol works, use the RFC Index to look up RFC 1725, which defines the POP Version 3 mail interface standard.