POP3 vs SMTP vs IMAP

SMTP :

• Short for Simple Mail Transfer Protocol, a protocol for sending e-mail messages between servers. 
• Most e-mail systems that send mail over the Internet use SMTP to send messages from one server to another; the messages can then be retrieved with an e-mail client using either POP or IMAP.   
• It is generally used to send messages from a mail client  to a mail server. This is why we need to specify both the POP or IMAP  server and the SMTP server when we configure our e-mail application.

POP3 :

• The Post Office Protocol (POP) is an application-layer Internet standard protocol used by e-mail clients to retrieve e-mail from a server in an Internet Protocol (IP) network.
• POP version 3 (POP3) is the most recent level of development in common use. 
• POP has largely been superseded by the Internet Message Access Protocol (IMAP).

Advantages of IMAP :

• Read It Anywhere.
• Backed up & Safe.
• Most Email Clients allow us to download some or all of our email messages from the server to our local computer for viewing while we are not connected to the Internet, or for archiving without taking up disk space on our provider’s servers.
• Many operations such as sorting messages, searching, and moving messages between folders can be done by the server without requiring us to download the messages involved, thus requiring little bandwidth and making them very fast.
• All of the email that we keep on the server (even if it is sorted into multiple folders) can be viewed by either Web Mail or an Email Client using IMAP.

Disadvantages of IMAP :

• Internet Required.
• Disk Space.
• We must obtain, install and configure our Email Client software on each computer that will be used for checking our email via IMAP.

Advantages of POP3 :

• Because POP usually downloads all messages to our local computer and automatically deletes them from our email provider’s server, we minimize the amount of disk space that we use on the servers, possibly lowering the cost of our account.
• Once our email messages are downloaded on our local computer, wecan read them very easily and quickly, even if our computer is no longer connected to the Internet.

Disadvantages of POP3 :

• Since our email is downloaded to our local computer, we cannot view this email from any other machine.
• Software Required.
• We can't access on multiple devices.



	WebMail	IMAP	POP
Access Email From Anywhere?	Yes	Yes	No
Large Server Disk Usage	Yes, Unless we use POP as well	Yes	Minimal
Dependence on Internet Connectivity	Strong	Very Strong	Moderate
Special Software Needed?	No	Yes	Yes
Data Backup Responsibility	Service Provider’s	Service Provider’s	Ours
Security	Depends on Provider	Depends on Provider	Depends on Provider