The purpose of this page is to explain the advantages and disadvantages of using two different ways email behaves, POP and IMAP.
POP is typically used on laptops and computers, rarely on portable devices such as phones or tablets. IMAP is typically used on portable devices such as phones and tablets and user accessible accounts on servers.
Advantages of IMAP
Simplicity
- IMAP mail is synchronized across a user’s devices. Mail on the server is the same on all devices.
- IMAP mail that is moved to the Spam folder allows the mail server to refine its spam filters. Because IMAP mail is synchronized, that spam will be removed on all the user’s devices.
- IMAP mail can be stored in folders.
- IMAP users are spared from understanding how POP behaves.
- IMAP mail is the default for Apple devices and is easier to set up.
- IMAP spam deleted on one device is simultaneously deleted from the other devices.
Disadvantages of IMAP
Account Fills Up or Mail is Accidentally Deleted
- If unwanted mail is not periodically removed, the user’s account may fill up on the server resulting in mail bouncing back to the sender.
- If an email is accidentally deleted from one of the user’s devices or the server, it is deleted from all of them, requiring a restoration by email administrators if the restoration is performed in a timely manner.
- OlympusNet urges IMAP users to archive significant email to their laptop or desktop computers. For Apple users, mail may be archived in On My Mac mailboxes. The mail is then under their control where they can back it up locally. See Create or delete mailboxes in Mail on Mac.
Advantages of POP
Permanence
POP email is downloaded to a user’s laptop upon arrival at the server, then typically remains on the server for a finite period before it’s deleted from the server. The downloaded email remains on the user’s laptop until the user deletes it.
- POP mail is unlikely to fill up the user’s space on the mail server resulting in mail bouncing back to the sender.
- Because the mail is on the user’s laptop, it cannot be accidentally deleted by the user’s IMAP devices.
Disadvantages of POP
Complexity
POP users use IMAP devices for their phones and tablets, so they need to understand how POP and IMAP differ.
Specifically, POP users must understand the implications of the time mail is left on the server before it is automatically deleted.
If mail is deleted from the POP user’s Inbox, it will remain in the Inboxes on his IMAP devices. If the POP user wants consistency across his email devices, he must separately delete that email on his IMAP devices, thus deleting the same email twice.
No Spam Reporting to the Server
Moving spam from the Inbox to the Spam folder does not teach the mail server to filter future similar spam.