IMAP vs POP3 email accounts

What type of email account to use on my device, IMAP or POP3?


By default, most new iPhones revert to IMAP when setting up your email account.  While this is a great idea for corporations running their own mail servers, in a shared environment it is particularly wasteful, resource hungry for the hosting company and costly for the end user.

By way of example. using the physical postal service in comparison, with IMAP, you go to the Post Office and take a copy of all the letters there and leave the originals in the mailbox. If you then go away and write a letter, you would then take a copy of it and put it into the P.O. Box. Can you see an issue with doing things this way? Yep, at some point that mailbox just can’t hold any more mail. When that happens any incoming email gets rejected and your email stops working. If you have a phone or device that is connecting to the mail server using an IMAP connection and you have a LOT of email then you could have a big problem.

So what’s the problem?
The standard size server mailbox for a default email account is 250Mb but some of the people that manage their domain/website and email via cPanel are setting the mailbox size limits to greater than the 250Mb default, even making them unlimited. The result is that we are  seeing IMAP users with an increasing number of mailboxes with over 1Gb of email stored in them. This causes some major potential problems for the end-user:
1: High element of the risk of losing all your email should the file become corrupt.
2: Slow access times
3: Inability to retrieve email during a resynch
4: Need to resynch on phone upgrades can take many hours.
5: Local network effects such as slow performance and disconnections
6: High Internet access/phone account costs.

7. Synchronisation takes longer the more mail is stored
IMAP accounts were never designed to be used as they are today and unless strictly managed they can cause huge jumps in costs. Mobile phones and some operating systems default to IMAP accounts when configuring your email connection on your mobile device (and some desktop email programs) and this means that all your messages are duplicated – one copy on each of your devices, and one on the server.
When you think about just how much email you keep the volume of it can be huge and it’s the synchronisation of this large volume that introduces the hidden costs.
A PREMIUM hosting account with JAG Systems allows for 5Gb of storage and if you have 10 employees all collecting email and using IMAP on their phones then you can see that if they do not manage their mailbox/phone inbox capacity it can easily blow out the hosting account allowance. When that happens all services for the domain are shutdown, website, email, everything. Your business goes off the air.


The basis of POP3 accounts is that you check your mail and it downloads everything from server Inbox and then clears them from the server so the mailbox is left empty. In our P.O. Box corollary, it’s like going to the Post Office, opening the P.O. Box and removing all the mail. The P.O. Box is then left empty.
POP3 accounts do have the facility where you can leave a copy of the messages on the server for a specific time or action (like deleting the message) and this is how you would setup the email account on your phone. Then when you check your mail with your phone, you get a copy of all the new messages but a copy is also left on the server for when you check your mail through your PC. Your office/home computer can be set to delete the messages from the server after downloading thus leaving the mailbox clear One of the devices MUST BE set to remove the messages in order to clear the server mailbox and that device should be the one that does most of the business related work.


So which is best, IMAP or POP3?
IMAP seems like the ideal because you can get access to all your email all the time and that is great if:
1) You are very efficient with your email and delete everything you don’t need.
2) Don’t get a lot of email.
Where it’s bad is that we are not efficient at managing our email and we are getting lots and lots of emails with attachments that we tend to keep. Like that crazy 10mb video attachment your mate sent you. You probably don’t realise it but your inbox is more than likely the best part of 1Gb so think what happens when you upgrade your phone or have to reset it. You lose all your email on the phone so it then has to synchronise the entire 1Gb as soon as it reconnects. That’s 1Gb of data that has to be downloaded to your phone. Even at 4G speeds it’s going to take hours if not days and while it’s doing that you can’t read any new emails. And that volume contributes to the total bandwidth that is being drawn from the server and may tip you into needing to increase your bandwidth and its cost, plus incurring possible networks charges from your phone provider. Telstra mobiles can really catch you out on things like this. A good inbox size to think about for an IMAP account is 200Mb or so. Bigger than that and you should really be thinking about going POP.

POP accounts let you have huge inbox sizes on your PC because you are not limited to the server capacity. But the disadvantage is that while you can read all the mail on your home/office PC, on your phone you can only read what has been downloaded onto your phone, not everything.
And the winner is…
In my experience working on both sides of the system, POP is a far more efficient and manageable. Whichever way you go whatever email protocol you chose, be it IMAP or POP, make sure that ALL your devices use the same one, ie all POP or all IMAP. Do not mix IMAP on one device with POP for the same email address on another device. You will get all sorts of issues.


If your mailbox is getting excessively large, archive unwanted mail to a local folder on your device.