Ongoing discussion on MIME takes place in the newsgroup comp.mail.mime . The MIME FAQ contains an appendix with useful information about MIME types. Before sending mail from a mail client to the internet, the SMTP server must me assigned. Furthermore, the SMTP protocol regulates the transfer of messages between mail servers, directing a message to its final destination. POP3 is the most recent version of the POP protocol, and is described in RFC-1725 .
POP is the oldest and best known message protocol.
There have been two versions of POP thus far. The first called POP2, became an email standard during the 80's, and was defined in RFC-918 in October 1984. When a user or email client checks their inbox, a connection is made to the mail server, and the new messages are download to the local drive, and deleted. POP makes electronic mail easier on mail servers by decreasing server usage and maintaining more server storage space, making it a favorite of many System Administrators, but not the most powerful protocol available for end-users. This is where IMAP comes in.