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 allows you to download mail from other mail servers into a local account on Ocean Mail Server. 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 different kinds of POP3 retrievals in Ocean Mail Server: Automatic POP3 Retrievals and User POP3 Retrieval. Both are used in several different ways.

Automatic POP3 Retrievals
The most common use of POP3 retrievals are automatic POP3 retrievals which are configured in the POP3 Retrievals service. Each of these POP3 retrievals are simply polled at a regular time interval called the ‘Poll Frequency’.

User POP3 Retrievals
User POP3 retrievals are fundamentally identical to automatic POP3 retrievals other than instead of being retrieved at a regular interval they are triggered by events. The different event triggers are enabled in the group options. These include login triggers for each service and manual triggering via a button when logged into WebMail.

Automatic vs. Triggered
Automatic retrievals are done periodically instead of triggered at logins. This has a couple of advantages over triggered retrievals. Firstly, the user doesn’t have to wait for processing of POP3 retrievals at login time because the mail will already be in their account. Secondly, since triggers are done once the user logs in, POP3 will not be made aware of any new mail arriving via POP3 retrievals until the next time the user logs in. This is because POP3 mail clients usually check for mail once, download them and log out. On the other hand, triggered POP3 retrievals are beneficial to IMAP4 and WebMail because new mail is checked for at login and will show as soon as the appropriate folder is refreshed. WebMail benefits the most by also being able to trigger for POP3 retrieval checks at any time.

Security Considerations
As you might guess from the name, POP3 Retrievals uses the POP3 protocol to connect to other mail server to download mail. You should be aware that POP3 Retrievals downloads new mail from the host mail server and then deletes the mail from the host mail server. This is the way POP3 is nearly always used in mail clients. In this case, this is essential because if the new mail was not deleted, the same mail would be retrieved more than once.