Q. What's the difference between a POP and IMAP type account?

A. When you create a new account in your email software, you are normally given the option to setup a POP or IMAP type account. The differences between these types of accounts are as follows;

POP - This type of account is what we usually recommend for users of @gol.com email accounts. The reason for this is that POP type accounts are usually setup to remove mail from the server which prevents the mailbox from being filled. The default mailbox size for @gol.com accounts is 100MB so if mail is kept on the server for too long, the account will become full and any new mail will be rejected.

POP accounts can be setup to remove mail from the server immediately after downloading it, after a certain time period (e.g. 1 week), after a certain action (e.g. deleted from the Trash folder) or they can be setup to keep mail on the server indefinitely. In most cases, we recommend that mail is removed from the server immediately or after a short period of time to prevent full mailbox problems.

If you have applied for and are using the Mail Plus service which increases the mailbox size from 100MB to 200MB and up to 3GB, it's possible to keep the mail on the server for a longer period of time. If you are planning on keeping mail on the server indefinitely, we usually recommend using an IMAP type account. The reason for this is timeout errors can occur when there is a very large amount of mail on the server and you are connecting with a POP type account.

IMAP - This type of account is used when you want to keep all email on the server, i.e. received messages, sent messages and trashed messages. In this case, the email software connects to the server and synchronizes with whatever mail is stored there.

The advantage of IMAP is that it makes it very easy to synchronize the mail account when checking it from different computers or devices. For example, if you are using a laptop and a smart phone to check your email, you may want to be able to see all received, sent and trashed messages on each device. Using an IMAP type account allows you to do this. If you were to send a message from the laptop, this sent message would then be stored on the server as well. When you then connect to the server with the smart phone later, the sent message will appear in the "Sent Messages" folder on the smart phone as well since this has synchronized with the data on our server.

The main thing to note is that when you are using an IMAP type account, any change you make on any device will be reflected on the server and then any subsequent device that connects to it. This also means that if you login to our Webmail site and delete a message here, the message will then be deleted on the other devices connecting to the server.

Since an IMAP type account requires mail to be stored on the server, we do not recommend this type of account unless you are using the Mail Plus service as it is very easy for the mailbox to be filled.

Mixing POP and IMAP Accounts

There are some cases where an email account has been setup in 2 (or more) different devices with one of them setup as a POP type account and the other as an IMAP type account. In most cases, it is better to use IMAP when checking email with multiple devices or to be consistent with accounts, for example when using POP on multiple devices, make sure they have been setup to remove mail after the same period of time.

In cases where a mix of POP/IMAP accounts have been used, the following issues can occur;

- Any messages that are deleted via an IMAP account are moved only to a "Trash" or "Deleted Messages" folder on the server. Any messages that are deleted via a POP account are immediately removed from the server and sent to a local "Trash" folder on that device. This can cause inconsistencies between the 2 accounts, particularly when checking the "Trash" folder on an IMAP enabled client.

- Any messages that are sent via an IMAP account are stored on the server in a "Sent" folder. Any messages that are sent via a POP account are stored on the local device in a "Sent" folder. Again, this will cause inconsistency between the 2 clients as messages in the "Sent" folder on the server cannot be seen by the POP enabled client as POP will only check for messages in the Inbox, not any other folders. In addition to this, any messages sent via the POP enabled client and stored in the local "Sent" folder cannot be seen by the IMAP client as the "Sent" folder for the POP account does not get synchronised with the server.

- Any messages that are moved from the Inbox to another folder (e.g. a folder called "Travel") on an IMAP enabled client, can no longer be seen by any POP enabled email clients. This is because the POP type account will only check the Inbox itself and not any sub-directories of this. This also includes any automatic filtering by the IMAP enabled client where this client has rules inside of it to move messages to a specific folder based on the sender address, subject or any other particular flag that has been set.

There are rare use cases for using a mixed POP/IMAP type environment but we would recommend using either POP or IMAP on all devices for consistency.

Tags: email, imap, pop