Alpine is the University of Washington's "Alternatively Licensed Program for Internet News and Email." It is intended to be an easy-to-use program for sending, receiving, and filing Internet electronic mail messages and Internet News (Usenet) messages. Alpine supports the following Internet protocols and specifications:
MIME allows you to attach any kind of file to your message, provided that your recipient also has MIME-capable mail software (which is readily available for most types of computers, although some proprietary mail systems do not yet support MIME). IMAP allows access to mailboxes on remote mailservers as if they were local.
Although originally designed for inexperienced email users, Alpine has evolved to support many advanced features. There are many (perhaps, too many) configuration and personal-preference options, though which of them are available to you is determined by your local system managers.
Alpine is a "mail user agent" (MUA), which is a program that allows you to compose and read messages using Internet mail standards. (Whether you can correspond with others on the Internet depends on whether or not your computer is connected to the Internet.) Alpine also allows reading and posting messages on the Internet Usenet News system, provided that your site operates a suitable news server, which is becoming rarer and rarer.
A "mail user agent" such as Alpine is just one part of a messaging system. Here are some things that are not done by Alpine, but require other programs:
Alpine's message composition editor is also available as a separate stand-alone program, called PICO. PICO is a very simple and easy-to-use text editor offering paragraph justification, cut/paste, and a spelling checker.
Alpine's built-in file manager - used, for example, to select a file for retrieval into the body of a message being composed - is available as a stand-alone program for Unix hosts, called PILOT (for "AlPine's Lister of Things").
MIME (Multipurpose Internet Mail Extensions) is an Internet standard which allows transfer of binary files (word-processing documents, spreadsheets, images, sounds, etc.) between any compliant mailers, such as Alpine. You can get technical information about MIME from the section Multipurpose Internet Mail Extensions (MIME) in the Alpine Technical Notes.
Ongoing discussion on MIME takes place in the newsgroup comp.mail.mime. There is also a Frequently Asked Questions (FAQ) list about MIME that is posted regularly to the newsgroups comp.mail.mime, comp.answers and news.answers, and also accessible at the URLs:
The MIME FAQ contains an appendix with useful information about MIME types.
IMAP (Internet Message Access Protocol) is a method of accessing electronic mail or bulletin board messages that are kept on a (possibly shared) mail server. In other words, it permits a "client" email program to access remote message stores as if they were local; Alpine is such a client. For more details on IMAP, please visit the World Wide Web site The IMAP Connection at the URL: http://www.imap.org/
SMTP (Simple Mail Transfer Protocol) is the standard protocol used for sending email. SMTP was defined in 1982 in RFC-821. The definition has been modified by many later RFCs, such as RFC-5321, RFC-1869, and RFC-1891.
POP3 (Post Office Protocol 3) is an older protocol for downloading electronic mail from a mail server, and is described in RFC-1939. POP3 is gradually being replaced by IMAP but Alpine does support POP3.