What is an IMAP Email?

By Peter Mitchell

IMAP stands for Internet Message Access Protocol. It's a way to access your email account remotely, without having to download all of your messages onto your computer. Along with POP3 and web mail, IMAP is one of the most common ways to access email on the Internet. Government departments such as the National Institute of Standards and Technology's Computer Security Resource Center consider IMAP email a more convenient alternative to POP email.


According to the University of Washington, IMAP was first developed in 1986 at Stanford University by developer Mark Crispin. It was then improved and refined over the next decade. In 1994 the version IMAP4 was accepted as Proposed Internet Standard. IMAP was then adopted more widely from 1995 and beyond.


IMAP email is stored on a central mail server. That means you can read and search your email from anywhere online. IMAP supports online, disconnected and offline access. To use IMAP, you need email client software that is IMAP-enabled. Popular email client applications such as Microsoft's Outlook Express and Apple Mail work with IMAP.


According to the IT Services Department at Stanford University, IMAP mail is particularly useful for people who need to access mail at multiple locations. For example, you might check your mail from a laptop while traveling, a desktop computer at home and another machine while at work. IMAP offers the convenience of being able to access all of your mail, both new and old, on any machine.

POP3 and Webmail

POP stands for Post Office Protocol. Unlike IMAP, POP accounts require you to download emails to your computer before viewing. This means that you can't access your account anywhere. POP3 is mainly designed for people who use only one computer and who use Thunderbird, Outlook or Eudora software to check their email. Webmail stores your email on a central server, much like IMAP. However, unlike IMAP, web mail generally does not allow for easy downloading of email to a local machine.


Because IMAP email is stored on a server, most accounts will set a storage limit. You can download data to your machine at any time for future reference or as a backup. Delete items from the server to free up more storage space. When downloading messages to your email client, you can choose to receive message headers only, speeding up the process.