POP3 vs IMAP

Setting up an email account on a third party client (most commonly: Microsoft Outlook for PC, Mail for Mac) seems like it should be easy.  You put in your login, password, incoming and outgoing server information and viola! However there is one step that can be a bit confusing.

Do I select IMAP or POP3?

Here’s the basic rule of thumb:

Use POP if you access your email from one computer only.  Use IMAP if you want to access your mail from multiple computers or locations.

IMAP stores mail on email servers, POP stores email on the users computer.

POP (or “Post Office Protocol”)

With the POP protocol, email is stored on the server until the user downloads their mail using a mail client (Outlook, Mail for Mac).  At that point the mail is typically removed from the server (although many third party applications now allow you to change that setting to leave a copy of the mail on the server).  Typically, the mail is “popped” off of the server and on to your computer. It was created so people could go online, download their mail and sign off, allowing the user to read the emails while offline.

Advantages of POP

• Allows the user to keep a copy of their email downloaded on their computer ( can be a good thing or a bad thing, depending on how you look at it, but I like this feature)
• By downloading the email, you free up server space

Disadvantages of POP

• Once your message is removed from the server by one computer, you cannot access it from another computer.

IMAP (or “Internet Message Access Protocol”)

With the IMAP protocol, email is mirrored or “synced” with the mail on the server.  You never download the messages to your computer and need to be connected to the internet at all times to manage your mail.  If you delete a message, it gets deleted from the server.  Email management takes place all on the server side. Since the mail stays on the server, you can access the same mailbox from any other computer with an internet connection.

Advantages of IMAP

• Can be accessed in multiple locations or by multiple computers
• Can be accessed by multiple users as a “group” email account

Disadvantages of IMAP

• Resides on server at all times, which takes away from storage space on server
• Cannot download email files on to a computer

Some Key Differences

POP – one user, one computer
IMAP – multiple users, different computers

POP – downloads mail to computer
IMAP – stores mail on server

POP – Organize mail in folders on users computer
IMAP – Folders can be organized on the server side

It is great to have these two options and once you understand the difference, you can feel more empowered the next time you set up an email account.