When evaluating the differences, advantages, and disadvantages of IMAP and POP3, you need to consider the type of user who will use email, how it will be used, and the internet access available to the user.
To make it easier for you to find the one that best suits your needs, we will discuss a few points about each protocol.
IMAP (Internet Message Access Protocol)
The most significant feature of the IMAP protocol is that your emails and mail folders are not on your computer but on the Cloud Server. This keeps all your emails perfectly synchronized when you normally read email from different computers or devices, or even from Webmail, since all your emails will appear on any of them, including not only emails in the inbox but also those in all other mail folders.
The main disadvantage of the IMAP protocol is that you need an Internet connection at all times to check messages. In addition, since they remain stored on the server, you need to check the space used by emails from time to time to avoid exceeding the capacity limit of the mailbox in question.
In any case, this disadvantage is “corrected” when using certain email programs such as Microsoft Outlook, since you can enable the “Autoarchivar” feature to prevent the mailbox from filling up, as it will automatically delete older or expired emails or store them in local folders.
ADVANTAGES
- Two-way communication between the mail server and the email client, allowing multiple devices to work with the same account and see the changes made by all of them.
- Emails are on the server at all times, so they can be accessed from anywhere with a device that has internet access.
- If the computer on which the mailbox is configured breaks down, or if the account is deleted for any reason, it is always possible to recover the emails.
- Since emails are not downloaded directly to the device accessing the mail server, no local space is used.
- It is possible to manage local folders and files from the server.
- It allows searching for messages using keywords.
DISADVANTAGES
- Emails cannot be accessed without internet access.
- Heavy use of the email service requires a large amount of storage space on the server.
- Folders created with IMAP cannot be read using POP (the only exception is the Inbox folder).
POP3 (Post Office Protocol)
With the POP3 protocol, the email client program (Outlook, ThunderBird, Mail, etc.) connects to the server and downloads all emails to the device on which you configure the account. This is its main advantage, since downloading emails allows you to read them even when you are not connected to the Internet.
As additional background, POP3 is a protocol developed when Internet connections did not have flat-rate pricing, so the goal was to download email and disconnect immediately, without having to connect every time you wanted to check your email.
When messages are downloaded from the server each time you read your email, they are deleted from the server, freeing up space on it, so there is less chance of the mailbox filling up, leaving you unable to receive new emails. However, there is now an option to keep a copy of messages on the server to synchronize incoming messages so you can check email from different devices.
ADVANTAGES
- Being able to use an email client to download emails to a device or computer and read them later, even without an internet connection.
- You do not need a large amount of storage space on the mail server, since emails are deleted from it when downloaded.
DISADVANTAGES
- If the device storing the downloaded emails breaks down, is lost, or is stolen, the emails are lost.
- Sending a message from the client can take twice as long.
- Depending on the message, it may consume system resources.