Email
handling can be done through different methods which technically are referred
as Protocols. These protocols are used for either receiving the emails or
sending the emails. IMAP and POP protocols are used for receiving the emails
and SMTP protocol is used for sending the emails. When any user sends an email, the mail message
is moved from the front-end email client to the mail server. This mail server
will then use the destination email address to track the
destination. So the emails will be stored to the mail server unless your mail
client demands to download it. Here IMAP and POP play an important role.
POP:
When
users use computers, none of them utilize these computers all the time.
Computers are not online all the time and are turned off when necessary. POP
(Post Office Protocol) is an Internet Standard for retrieving emails from the
mail server where it is stored temporarily. In case all the computers were
supposed to be online, protocols like POP wouldn’t be useful at all. This is
because in that case the emails would have delivered directly to the
recipient’s computer. But the problem is computers are turned off mostly and
because of this, emails have to be stored somewhere else unless user is online
again. POP performs the interaction between front-end client and server which
is holding the email messages.
POP
(Post Office Protocol 3) gives a standardized way for users in order to access
mailboxes by downloading them to the computers. It works in three states;
Authorization, Transaction and Update. While using the POP protocol, the email
messages will get downloaded from the server to the local system. As emails are
saved to the system, one can easily access the emails even when internet is
unavailable.
IMAP:
IMAP
(Internet Message Access Protocol) is another Internet Standard for receiving
or we can say retrieving emails from the email server. IMAP email client
generally saves the email messages by downloading a copy of the messages from
email server to the local system but keeps a copy of the messages in the cloud
server as well. The difference is that IMAP email client will regularly
synchronize local mailbox and mail server (cloud). In case any message is
deleted from the local mails, it will be deleted from the cloud as well when
both of these platforms (email server and local mailbox) are synchronized.
The
most important feature of this IMAP email client is that the user can access
the emails from more than one location or device. This is because the emails
are stored in the email server and hence can be access through Mobile, system
in another location, etc. Emails are stored in the central server and hence can
be accessed anytime. Users can access the emails at home and work-station as
well.
SMTP:
SMTP
(Simple Mail Transfer Protocol) is the standard used by Mail Transfer Agent for
sending emails and while using the SMTP, email messages are transferred from
client to SMTP server. The messages can be then moved from one SMTP server to
another also. IMAP and POP3 are used for retrieving the emails from SMTP
Server. The most common model for SMTP is it using the TCP Transport service in
TCP/IP suite. Emails which reach to SMTP are either forwarded to remote server
or it is delivered to local mailboxes on the local server. The SMTP protocol is
only used for sending emails and not for receiving them.