Knowledge Essentials - 3Essentials Hosting


Article ID: 1459

 Back to Search

Question: Should I configure my email to use POP or IMAP?


Terms needed for this article:
email client: the email software you have on your computer (or other device) that will retrieve your email via POP or IMAP.
mailbox: the space on the mail server where your email for your specific email address is kept.
postoffice: collectively refers to all mailboxes for your domain (,,, etc)

POP is the traditional method, but IMAP is being used more frequently due to growing use of cell phones as a secondary method for accessing a given email address.

POP generally downloads messages from your email account's inbox on the server to your email client, and deletes the message on the server.  Depending on the mail client, there may be advanced POP options to modify this behavior:
- delete messages on the server when downloaded (usually enabled by default)
- delete messages on the server when downloaded after X days
- other...

IMAP doesn't download messages, it's more a window to view the messages as they sit on the server. 

To illustrate, consider this example:
  • you receive 1 email in your inbox.- you check your mail with your computer from home, which you have configured to POP your email, with POP set with the default "delete message on server when downloaded"
  • during that connection, your computer downloads a copy of that message, which it will then keep locally for you to review, and sends the mail server an instruction to delete the copy of the message on the server.
  • later, you check the same mailbox from your phone, using IMAP.  it will not find that message, because it was already deleted by the earlier POP connection.
  • later that day, you're back on your home computer, reading the email message you downloaded via POP earlier to your home computer's email client.  You DELETE that message... it's deleting the message from your computer, not the server... because it was already deleted from the server earlier in the day when you initially POP/downloaded it. 
For some folks, this works fine, as they only want to see messages on their phone when they are away from their home computer.

Another example:
  • you receive 1 email in your inbox.
  • you check your mail with your computer from home, which you have configured to IMAP your email.
  • later, you check the same mailbox from your phone, using IMAP.  It WILL find the message, because the earlier connection from your home computer just viewed it as it sat on the server.
  • later, you DELETE the message via your home computer with IMAP, that deletes the message from the server itself, and it will no longer be accessible from your computer or your phone, as it no longer exists on the server.
Think of IMAP as managing the messages as they reside in your mailbox on the server. 
  • benefits: you can access that mailbox from multiple locations
  • drawbacks: growing mailbox size if you don't keep up with your email... with shared hosting, we do impose a maximum post office size (all mailboxes for your domain) of 2GB.  IMAP users have a tendency to not delete their emails and just let them grow and grow and grow.
Think of POP as downloading a copy of the mail to your PC/email client.
  • benefits: you have a local copy of the mail message, you can retain it as long as you want and not worry about growing size of your email (other than limitations of your PC's email client, or your computer's hard drive space)
  • drawbacks: once you've downloaded the message to your PC, it's no longer on the mailbox on the server to be accesesed via webmail or another email client using IMAP.
So, which to use, really depends on your particular needs for managing and accessing your email.
Downloads Associated With This Article
No downloads are currently associated with this article.