Over the past year or so, I’ve spent a lot of time on various e-mail related forums. I’ve seen many posts similar to “Help! I’ve marked a message as read in my email client, but it’s still not marked as read on my iPhone/BlackBerry/other computer.” In 9 out of 10 cases, this is simply because the user is using POP3 instead of IMAP. This leads me to wonder: why the heck are people still using POP3?
Today, with the exception of some ISPs and low-end free email services, most providers support IMAP. Assuming your email provider does support IMAP, why would anyone pick POP3 over IMAP? Is it purely because of old habits, miseducation, or is there an actual reason?
Let’s go through the basics of POP3 versus IMAP first. In many ways they are similar. However, they differ in one significant way: POP3 was built to let the server hold your email until you download it (and then delete it) while IMAP was built to actually store your emails on the server.
From a provider’s point of view, it makes a lot of sense to recommend POP3 over IMAP. The more users pick POP3 over IMAP, the less storage the email provider will need (which is why many ISPs only offer POP3). Their costs will go down. Moreover, the importance of redundant storage decreases, as a meltdown in the datacenter only means the loss of messages waiting to be downloaded instead of the entire email archive. The enduser is responsible for maintaining backups and providing storage.
From a customer’s point of view, I can only think of one rational argument for why someone would pick POP3 over IMAP. That argument would be storage quotas. If you use POP3 (and chose not to leave the messages on the server), you will never run into a problem with storage, even if your provider offers a fairly low storage quota. The reason for this is obviously that the messages are not stored on the server, but rather on your local machine. Hence, the ‘quota’ for POP3 is your local machine’s storage capacities.
A common myth is that IMAP is harder to set up than POP3. This is really nothing but a myth. For instance, in Thunderbird, the steps of setting up a POP3 or IMAP account are pretty much identical. Perhaps setting up IMAP was more difficult than setting up POP3 in the past, but today, that’s really not the case.
So what does IMAP offer that POP3 does not?
Synchronization across multiple devices
Today most of us have at least two devices to check our email with (e.g. a desktop client and an iPhone). If you’re using IMAP, when you mark a message read on one device (be it your iPhone or your desktop client), it will automatically be marked as read on the other devices too.
Allows you to stay more updated
Today, most IMAP servers support something called IMAP IDLE which means that instead of having to check in with the server every n’th minute, the server will automatically tell the client that a new email just dropped in. There’s also Push-IMAP, which is even more sophisticated.
A free backup of your email
The way I think of it, IMAP offers a free backup of all your emails. As many Sidekick users recently learned the hard way, you should not rely on just one instance of your data (even if it’s in the cloud). IMAP offers one ‘free’ backup of your email in addition to your local copy. If you’re using POP and the hard drive of your local machine decides to stop working, all your emails are gone (assuming you do not have backups). That said, it is still wise to make copies of your email to a secondary IMAP server. I personally use YippieMove to make a complete backup of all my email to a secondary IMAP server every other month or so. (Full Disclosure: Email Service Guide and YippieMove are both owned by WireLoad, LLC.)
With all of this in mind, I can really not think of any rational argument for why someone would pick POP3 over IMAP (other than lack of knowledge). Moreover, if your provider does not support IMAP, it is probably time to switch to a more modern provider that does anyways. The majority of the providers in our database do support IMAP.
Update 1: This article started a really interesting discussion over at Email Discussion.