POP3 (Post Office Protocol version 3)

An IETF standard (RFC 2449) for a store-and-forward

service used by a client to retrieve e-mail from a remote server over an IP network. Prior to accessing a mailbox at the remote server and downloading all mail to the client, the user can elect either to delete downloaded mail from the server or to leave a copy of each on the server. After downloading mail, the user can disconnect from the remote server and work with the mail offline. POP3 is used only when downloading mail from the mailbox.When uploading mail, client access is to a server running Simple Mail Transfer Protocol (SMTP), which simply forwards mail after looking up the proper IP addresses on a Domain Name Server (DNS) server.While POP3 is widely implemented, the more recent Internet Message Access Protocol (IMAP) offers certain advantages. See also client, DNS, e-mail, IETF, IMAP, IP, RFC, server, and SMTP.

• press-to-talk (PTT)
• press-to-talk (PTT)
• presubscription
• presubscription
• pretexting
• Pretty Good Privacy (PGP)
• primary rate access (PRA)
• primary rate interface (PRI)
• primary/secondary
• printed circuit
• printed circuit board (PCB)
• priority ringing
• PRI (Primary Rate Interface)
• privacy
• privacy key management (PKM)
• private automatic branch exchange (PABX)
• private branch exchange (PBX)
• Private Integrated Services Network (PISN)
• Private IP
• private IP address
• private key encryption
• private paging operator (PPO)
• private port
• Private Signaling System No. 1 (PSS1)
• Private UNI (Private User Network Interface)