What is the difference between POP3 and IMAP?

If you have ever set up an email account you will remember being asked if you want to set it up as an IMAP or as a POP3 and you always choose POP3 but you have no idea what the difference is. Well here is a short explanation of what both are and what the advantages and disadvantages of both are.

POP3

POP3 has been around for many, many years and is the most popular way to receive emails. It stands for Post Office Protocol.
Pop is a way of accessing your emails, it allows you, the email client to connect to the server, download your emails, your emails are stored on your computer and then disconnects. Depending on how you set up your email client the emails will either be deleted from the server or stored and then removed after 7, 14 or as many days as you can specify. You can respond and edit your emails without having to be connected to the server all the time.

Advantages of POP3 are:

  • It keeps the size of emails on your server to a manageable size.
  • All emails are stored on your computer so if you are offline and need to access an email urgently you are able to do so without any problems.
  • You can write an email and save it in your drafts to send later.
  • Any email client you may want to use to view your emails supports POP3 for example Outlook, Thunderbird, Windows Live Mail or even Mac Mail.
  • All attachments are downloaded automatically and stored in your email client so you can access them even when offline.
  • There is usually no limit to the size of the emails you send but depending on your internet service provider and bandwidth speed.
  • There isn’t a maximum size of storage on your mail client but also depending on your hard drive size.


Disadvantages of POP3 are:

  • Once you have downloaded your emails you cannot access those emails from another computer.
  • If you have problems with your computer and you need to reinstall everything without having a chance to create a pst all you emails are gone.
  • You don’t have much privacy as all your emails are sitting on your computer and anyone that access the computer can access your emails.
  • One other problem is viruses, because all your emails are downloaded to your computer there are chances of someone sending you spam that may contain a virus.

IMAP

IMAP is something that is a little more recent and it stands for Internet Message Access Protocol. IMAP method of retrieving emails leaves a copy of the email on the server instead of deleting them when downloaded. You always have a saved version of your emails on the server in case you lose your emails for some reason or need to access your emails from multiple computers or clients. This may also cause a problem on your server, if you don’t go onto the emails on the server and delete them regularly they may build up to an unmanageable size and slow your server down.

Advantages of IMAP:

  • With IMAP you can set up certain server side filters so that certain emails from certain clients go to a specific mail box and this can be done for all emails. So now if you’re at work and only want to receive emails from clients you can access just those email and at home just your personal emails.
  • All emails are stored on the server so you will never lose any of your emails if your computer breaks.
  • You can access all your emails where ever you are and from multiple computers.
  • If you read a computer on one computer it will show as read on all computers. Same with replying to emails the reply will be available to all computers you are working on.
  • If you receive an email with an attachment and you don’t want it to be downloaded you don’t have to download it.

Disadvantages of IMAP:

  • If you don’t delete emails from the server regularly you will have a huge amount of unmanageable emails on your hand and maybe even to the point where it will slow your server down.
  • You are unable to read and respond to your emails while you are offline.
  • Sometimes you might have to wait a while for your email client to sync if you are using the email account on multiple email clients.
  • If you are using an old computer and old software you will not be able to use IMAP.
  • Also only certain email clients support IMAP