How does the pc-remote milter service work?

Question

How does the pc-remote milter service work on a Plesk server? Is it possible to safely remove this service?

Answer

The pc-remote is essential for mail service on the server.

Note: the Postfix will not accept incoming messages and will not process the mail queue if this service is absent or down.

The Postfix connects to the pc-remote when the sender connects to the server before the message is saved into the mail queue, before the message is sent to a remote server and before the message is delivered to the local mailbox. Each time, Postfix submits the message to pc-remote and waits for a response.

• If the message passes all filters of a particular stage of mail delivery, the pc-remote gives it go and Postfix continues the delivery.
• If the message is matched by one of the filters, the pc-remote reports Postfix to reject the message.

Note: the pc-remote works only together with Postfix and will be automatically removed if the Qmail installed.