POP3

- POP3 services 1 Although most POP clients have an option to leave messages on the server after downloading a copy of them, most clients using POP3 simply connect, retrieve all messages, store them on the client device as new messages, delete them from the server, and then disconnect

- POP3 services 1 Although most POP clients have an option to leave messages on the server after downloading a copy of them, most clients using POP3 simply connect, retrieve all messages, store them on the client device as new messages, delete them from the server, and then disconnect

POP3 1 In computing, the 'Post Office Protocol' ('POP') is an application layer|application- layer Internet standard protocol (computing)|protocol used by local clients to retrieve from a remote mail server|server over a Internet protocol suite|TCP/IP connection. POP has been developed through several versions, with version 3 ('POP3') being the current standard.

POP3 1 Virtually all modern clients and Server (computing)|servers support POP3, and it along with IMAP (Internet Message Access Protocol) are the two most prevalent Internet standard protocols for e- mail retrieval, with many webmail service providers such as Google Mail, Microsoft Mail and Yahoo! Mail also providing support for either IMAP or POP3 to allow mail to be downloaded.

POP3 - Overview 1 A POP3 server listens on List of TCP and UDP port numbers|well-known port 110. encryption|Encrypted communication for POP3 is either requested after protocol initiation, using the STARTTLS|STLS command, if supported, or by POP3S, which connects to the server using Transport Layer Security (TLS) or Secure Sockets Layer (SSL) on well-known TCP port

POP3 - History 1 POP3 originated with RFC 1081 (1988). Its current specification is RFC 1939, updated with an extension mechanism, RFC 2449 and an authentication mechanism in RFC

POP3 - History 1 POP3 clients support Simple Authentication and Security Layer|SASL authentication methods via the AUTH extension

POP3 - Extensions 1 An extension mechanism was proposed in RFC 2449 to accommodate general extensions as well as announce in an organized manner support for optional commands, such as TOP and UIDL. The RFC did not intend to encourage extensions, and reaffirmed that the role of POP3 is to provide simple support for mainly download-and-delete requirements of mailbox handling.

POP3 - STARTTLS 1 The STARTTLS extension allows the use of Transport Layer Security (TLS) or Secure Sockets Layer (SSL) to be negotiated using the STLS command, on the standard POP3 port, rather than an alternate. Some clients and servers instead use the alternate-port method, which uses TCP port 995 (POP3S).

POP3 - SDPS 1 Demon Internet introduced extensions to POP3 that allow multiple accounts per domain, and has become known as Standard Dial-up POP3 Service (SDPS).[ help/mail/sdps-tech.html/ Demon Online Help Centre]. E.demon.net ( ). Retrieved on To access each account, the username includes the hostname, as or john+hostname.

POP3 - Dialog example 1 POP3 servers without the optional APOP command expect the client to log in with the USER and PASS commands:

POP3 - Related requests for comments (RFCs) 1 * RFC 5034 – The Post Office Protocol (POP3) Simple Authentication and Security Layer (SASL) Authentication Mechanism

Yahoo! Mail - POP3 1 Users from countries where there is a web browser access restriction can get around it by using software that simulates a POP3 server to which the application connects, such as YPOPs! and FreePOPs.

Yahoo! Mail - POP3 1 Another way of getting POP3 access without signing up for the paid mail plans is via Yahoo! Delivers, which sends the user promotional messages. According to the Yahoo! Mail help pages, Yahoo! offers POP access to Yahoo! Mail as a free feature exclusively for Yahoo! Delivers members. However, this applies only to users of Canadian Yahoo Mail extension of their mail.

Yahoo! Mail - POP3 1 As of October 2013, Yahoo provides paid subscribers POP3 access and forwarding.

RFC POP3 services 1 Although most POP clients have an option to leave messages on the server after downloading a copy of them, most clients using POP3 simply connect, retrieve all messages, store them on the client device as new messages, delete them from the server, and then disconnect.

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