Introduction The Post Office Protocol (POP) was first issued on October 1984. The protocol suggests a simple method for workstations to access mail from a mailbox server. The protocol is dependent upon TCP (Transfer Control Protocol) and assumes that mail is posted by SMTP. POP in more detail, is a way for a server machine to store and serve mail for various client machines that are not connected to the Internet 24 hours a day. This makes …showed first 75 words of 1444 total…

…showed last 75 words of 1444 total…for sending e-mail and either POP3 or IMAP for receiving messages that have been received for them at their local server. Since there are multiple ways of reading e-mail, there is a possibility that the two methods might clash with each other. SMTP is viewed as the primary method for e-mail delivery, and POP as a subordinate method for certain circumstances, and so the SMTP delivery method is not blocked while you are using POP.