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(messaging, protocol)
Version 3 of the Post Office Protocol. POP3 is defined in RFC 1081, written in November 1988 by Marshall Rose, which is based on RFC 918 (since revised as RFC 937). POP3 allows a client computer to retrieve electronic mail from a POP3 server via a (temporary) TCP/IP or otheronnection. It does not provide for sending mail, which is assumed to be done via SMTP or some other method.

POP is useful for computers, e.g. mobile or home computers, without a permanent network connection which therefore require a "post office" (the POP server) to hold their mail until they can retrieve it.

Although similar in form to the original POP proposed for the Internet community, POP3 is similar in spirit to the ideas investigated by the MZnet project at the University of California, Irvine, and is incompatible with earlier versions of POP.

Substantial work was done on examining POP in a PC-based environment. This work, which resulted in additional functionality in this protocol, was performed by the ACIS Networking Systems Group at Stanford University.

RFC 1082 (POP3 Extended Service) extends POP3 to deal with accessing mailboxes for mailing lists.


(Post Office Protocol 3) A programming interface (API) from the IETF that enables a user's e-mail program to access the mail server (RFC 1939 standard). E-mail clients such as Outlook, Mail, Eudora and Thunderbird are typically configured to retrieve mail either via POP3 or IMAP4, the other popular standard.

POP3 is a simple system with limited selectivity. Incoming messages and attachments are downloaded when users check their mail, and POP is typically configured to delete the messages on the server after downloading. If the user opts to not delete them, the messages will download again the next time mail is checked. See IMAP4, e-mail interfaces, SMTP and messaging system.

Incoming Mail Options
Most Internet mail services offer all three options. Users may choose IMAP if they need access from several computers or if they like to keep mail online indefinitely (see IMAP4).
References in periodicals archive ?
This will greatly appeal to business customers for access to email while travelling, when access to a POP3 mail client may be limited.
5 will feature a Microsoft Exchange Connector for POP3 mailboxes that allows users to download e-mail from ISP-provided POP3 mailboxes to Microsoft Exchange.
IVOICE Pro is also a versatile, 32-bit client that works with a variety of e-mail systems including Connect2, IMAP4, MAPI, POP3, SMF/MHS, SMTP, and VIM.
99 for those downloading the latest service pack update and can be configured for a wide range of POP3 email accounts like Gmail, Yahoo Mail, and mail services from other popular OSPs.
a leading provider of outsourced email services, today announced it is extending its offer of free Web-based email to Internet service providers (ISPs) who sign up for POP3 service by December 31, 1998.
have come to depend on from MetaInfo and Sendmail with POP3," said
Users accessing email from POP3, IMAP, Domino or Exchange 2000/2003 environments can receive, review, create, reply and delete messages directly from their devices, while Millennium users can receive automatic calendar updates, create new activities, view meeting details, set event reminders, and view, edit or add new to-dos, notes and contacts.
an international leader in IP management and messaging software for the Windows NT platform, today announced the beta release of Sendmail with POP3 for Windows NT v2.
Such connectors included are AIM, ICQ, MSN, YAHOO, IRC, POP3, IMAP, and many others.
Used in conjunction with MetaInfo's Sendmail with POP3, ListServer automates mass electronic mailings through its web-based interface and via "subscription" requests.
com, SMS messaging, POP3 Email access, VPN and Internet browsing.