ISPConfig 3 - Mail Flow
Can someone describe exactly how mail flows through the standard ISPConfig 3 setup? I have investigated the configs to some extent and have a basic idea, but there seems to be some redundancy I don't quite understand.
Here is my basic understanding:
Postfix receives mail, forwards to amavisd-new, which then scans with clamav, and spamassasin, and then sends back to postfix.....
Does postfix then send to maildrop for delivery? How can one verify this?
Is virus scan and spam filtering enabled globally by default unless turned off in a domain?
Also, how is getmail used exactly?
If this is documented reasonably straight forward somewhere I would be happy for a pointer.