Help, configuration and tips.

The POP3 Retrievals Service
When using multiple mail accounts on various mail servers, it can be tedious to have to login to many different locations to check your mail. POP3 Retrievals allow you to download mail from other mail servers into both local and external accounts. For local accounts, you can even specify which folder the mail will be placed in, allowing you to isolate mail from different locations to make your mail easier to manage.

When Are POP3 Retrievals Performed?
There are two types of retrieval in Ability Mail Server: automatic retrievals and user retrievals. Both of which can be used in several different ways.

Automatic POP3 Retrievals
The most common use of POP3 Retrievals are automatic retrievals, which are configured in the POP3 Retrievals service. These retrievals are polled at regular time intervals, of which the time length is referred to as the ‘Poll Frequency’. Automatic retrievals allow you to retrieve mail and deliver it to either local or external accounts. Also, it is possible with this type of retrieval to re-deliver the mail to the email addresses in the mail's header, allowing you to correctly manage remote catch-all accounts (see below).

User POP3 Retrievals
User retrievals are similar to automatic retrievals but instead of being retrieved at regular intervals, they are triggered by the user's activity and will also only ever be delivered into the user's account. The available triggers include the user logging into their account or manually through WebMail. The group options allow you to restrict which user actions count as a trigger.

Automatic vs. User
Automatic retrievals are done periodically instead of being triggered which means they have a couple of advantages over user retrievals. The most important advantage is that the user doesn't have to wait for processing of retrievals at login time, because the mails will already be in their account. Secondly, since user retrievals are usually only done when the user logs in, and a user is using the POP3 protocol to access their mail, the mail client will not be made aware of any new mail arriving until the next time they connect. This is because POP3 mail clients usually check for mail once, download them and log out. On the other hand, user retrievals are beneficial to IMAP4 and WebMail because new mail is checked for at login and also when the appropriate folder is refreshed. WebMail benefits the most by also being able to trigger a retrieval manually at any time. Another benefit of user retrievals is if the user account is close to the allocation limit, new mails will not be retrieved until some space is freed in the account. This adds a safety net against mails being lost due to allocation limits.

Remote Catch-All Accounts
A common scenario for many organizations is that all the mail addressed to a particular domain is stored in a remote POP3 account. Ability Mail Server allows you to link that account to locally stored accounts via automatic retrievals, ensuring that the mail gets re-delivered to the correct local user accounts. This is achieved by parsing the header of retrieved mails and using that information for delivery. To set this up you need only create a new automatic retrieval in the POP3 Retrievals service, configure the remote account settings, enable the option 'Enable Mail Header Delivery' and specify the domain or domains that the remote account holds mail for.

On Server Mail Deletion
As you might guess from the name, POP3 Retrievals uses the POP3 protocol to connect to other mail servers to download mail. You should also be aware that a retrieval by default, downloads new mail from the host mail server and then deletes the mail on the host mail server. If you wish to keep a copy of the mails on the server then you can enable the option 'Leave a Copy of Mails on the Server', which is available in both types of retrieval.