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POP
POP stands for Post Office Protocol. It is generally used to support a single client. There are several
versions of POP but POP3 is the current standard version.
Recipient e-Mail Server
MTA/e-Mail Client
SMTP
POP3 or IMAP
SMTP
Post Office Protocol version 3 (POP3) is a standard mail protocol that is used to receive emails from a
remote server to a local email client. It works similar to the physical version of a post office clerk, POP3
receives and holds email for an individual until delivered. POP3 allows you to download email messages
on your local computer and thus enables you to read them offline too. By default, the POP3 protocol
works on two ports:
Port 110: Non-encrypted POP3 port
Port 995: Encrypted POP3 port
IMAP
Internet Message Access Protocol (IMAP) is a mail protocol that enables to receive emails from a remote
server to a local email client. It allows to access e-mail messages without downloading them.
The advantage of using an IMAP mail server is that users can check their mail from multiple computers
and always see the same messages. This is because the messages stay on the server until the user chooses
to download them to his or her local drive. Most webmail systems are IMAP based, which allows people
to access both their sent and received messages no matter what computer they use to check their mail.
By default, the IMAP protocol works on two ports:
Port 143: Non-encrypted IMAP port
Port 993: Encrypted IMAP port
Do you know?
IMAP was originally known as the Interactive Mail Access Protocol. The name was changed to Internet
Message Access Protocol in IMAP4 version.
Networking 23

