Looking for a guide to collect all e-mail from the ISP mail server

[Michael Schumacher]

[...]
> I could not find anything there related to multidrop or "catch all" mailboxes.
[...]
> Nothing like that there either.
[...]
> This is a huge document with little introduction. It seems to be
> mostly about fighting spam. I did not find anything like the setup I described.

looks like the collective wisdom of this group can't provide precisely
what you are looking for. You may need to figure it out by yourself.

Btw., why is an open port 25 evil if the MTA is configured correctly?
Can you elaborate, please? 

best regards
---
Michael Schumacher