POP

Acronym: Post Office Protocol

Also known as "POP3"

Refers to the protocol for accessing mail in which all mail is downloaded directly to the client computer. Changes in read/unread, flags, etc. are not synched in real-time, but can be carried out through periodic polling. This protocol is especially useful for accessing mail with many attachments, as these files can be pulled down to the client computer, saving precious server disk space in the process.