Internet Message Access Protocol

Internet Message Access Protocol(or IMAP) is a set of rules that e-mail client programs, like the one in your computer, use to download email from a mail server. Another protocol which does the same thing is called Post Office Protocol but IMAP has additional features.

IMAP is a method of connecting to a server and reading incoming mail. Many modern e-mail programs support IMAP as well as the older POP3 standard. Our servers fully support either method — it’s up to you.

The two methods handle mail differently:

POP3 downloads copies of each message from the server to your computer, which then has its own separate copy of each message. Subsequent changes to that message on your computer don't affect the server or any other POP3 program reading the same mailbox. POP3 usually also immediately deletes all messages from our servers unless you take extra steps: since your computer has the only copy of the message, you need to rely on your own backups. IMAP always leaves the messages on our servers — in fact, the server copy is the main copy. However, you can have multiple IMAP connections to the server showing you that copy. The server knows when you've read a message, deleted it, replied to it, put it into a folder, and so on. Any other IMAP program reading the same mailbox (including our Webmail pages, which use IMAP behind the scenes) will know about all those changes. Most IMAP programs also keep a copy of each message so you can view previously received messages even without Internet access. The messages you've read are backed up using our backup system. We recommend IMAP if you’re using multiple devices or computers to read your mail, or if you’re using a modern e-mail program such as Mozilla Thunderbird, Apple Mail, or a recent version of Microsoft Outlook that’s optimized for IMAP. (Note that Outlook 2007 and earlier have poor support for IMAP, and we recommend using POP3 instead in older programs like that.)

The instructions we provide for POP mailboxes also apply to IMAP mailboxes. When you create a mailbox on our servers, the mailbox can be read using either a POP3 or IMAP connection.

To set up your mail program to use IMAP, you’d use the same server name, username, password, etc. The only changes are the connection method (choose IMAP instead of POP) and the port number of the incoming mail server (port 143 instead of port 110).

IMAP settings for particular programs These pages explain how to set up IMAP for some mail programs:

Outlook Express Outlook 2002 and 2003 (not recommended) Outlook 2007 (not recommended) Outlook 2010 Outlook 2011 for Mac Outlook 2013 Windows Live Mail Apple Mail Mozilla Thunderbird iPad and iPhone Technical details Technically advanced users may be interested in the following:

Our IMAP servers use the standard port 143 for normal IMAP. They also support optional TLS security on port 143 and pure SSL security on port 993. The IMAP folder prefix is "INBOX". Many mail programs will automatically detect this, but others may need you to enter this prefix into the account settings if you want to be able to use the same folders on your mail program via IMAP that you see in Webmail. The “capabilities” (IMAP extensions) supported by our servers are "IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE SORT SORT=DISPLAY THREAD=REFERENCES THREAD=REFS MULTIAPPEND UNSELECT IDLE CHILDREN NAMESPACE UIDPLUS LIST-EXTENDED I18NLEVEL=1 CONDSTORE QRESYNC ESEARCH ESORT SEARCHRES WITHIN CONTEXT=SEARCH LIST-STATUS".