What is IMAP? It is simply a way of accessing your e-mail. Right now, if you use Entourage, Outlook Express, Eudora, Apple Mail, or some other desktop client to read your e-mail you can use IMAP. However, unless you have a .Mac or Hotmail account, you probably use POP instead. But IMAP is better. Why? Because if you sometimes check your mail online, or on different computers, then IMAP lets you synchronize all your e-mail folders, not just your inbox. For instance, if you move a message from your inbox to a folder called “family” or “work”, that message will be in the “family” or “work” folder when you go to check your e-mail online, or on another computer! Similarly, if your host offers SPAM filtering, then e-mail suspected of being SPAM can be moved to a special “suspect” folder, and will not be in your inbox. You can even, on some servers, setup special filters that move all e-mail matching certain search criteria into designated folders. So, if you get lots of e-mail from a mailing list, you can move it all to a dedicated folder for that list and not have it in your inbox.
I am very happy with my IMAP service, which has amazingly helpful service, lots of cheap storage space, and close to 100% reliability. (In the last several years there was only one time that the service went down, and the problem was fixed almost instantly without any lost mail.) However, I just learned about a downside to using IMAP I had never thought of. This isn’t just true of IMAP, but IMAP users are more likely than POP users to keep lots of e-mail sitting online. The problem, explained in a report on Google’s new GMail service, is that it falls under the ECPA’s [Electronic Communications Privacy Act] “180 day rule”:
In the hoped-for event that your webmail archives are protected by the ECPA as what it calls an ECS, they lose some of that protection after 180 days. This is not news, but a product like GMail, which encourages long-term archving of e-mail with the web mail provider brings the question to the forefront. After 180 days your e-mail archives can now be fetched without a warrant, through a special ECPA court order or a subpoena. (In most cases, but not all, you will get notice of such seizures.)
That means IMAP is unfortunately less “private” than some other e-mail. But then, e-mail has never been very private to begin with…