POP3 and IMAP are two different protocols used to access email. POP3 and IMAP function very differently and each has its own advantages. POP3 is useful in checking emails from a computer that is in a specific location. IMAP is the better option when you need to check your emails from multiple locations, such as at work, from home, or on the road, using different computers.

Technology

• POP3 always downloads all new emails locally to your computer.
• IMAP downloads message summaries and doesn't download the entire message until you explicitly select it.

Email Display

• POP3 downloads all emails from webmail Inbox into one mail folder called "Inbox".
• IMAP preserves your webmail folder structure including "Sent" & "Deleted" folder.

Accessibility

• POP3 is useful if you only access your email from one computer, since the email is typically downloaded locally (this is the default and can be changed).
• IMAP allows email to be manipulated from a desktop computer at home, a workstation at the office, and a notebook computer while traveling, without the need to transfer messages or files back and forth between these computers.

Email Storage

• With POP3, your emails can be automatically erased from the server after they are downloaded freeing up space in your account.
• IMAP keeps all emails on the server until you erase them.

Which Do I Use to Set Up My Email?
Depending on your personal style of communicating, you can pretty quickly narrow down how you should use your email.

• If you use check your email from a lot of devices, phones, tablets or computers, set up your email clients to use IMAP.
• If you use mostly webmail and want your phone or tablets to sync with your webmail, use IMAP, as well.
• If you have multiple users who need to access the same email account, use IMAP.
• If you’re using one email client on one dedicated machine (say, in your office), you might be fine with POP3.
• If you have a huge history of email, you may want to use POP3 to keep from running out of space on the remote email server.