* I.:

How do you block emails when they come from a list address?

By not relying on the envelope sender address alone. Milters can inspect the complete message and signal the MTA to discard or reject it. For mailing lists, I use the former, so as not to generate bounces.

-Ralph

* I.:

That seems to be only possible with Linux, though.

It depends on whether or not the MTA supports the milter protocol. The various milters can be written in C, Python, or whatever strikes your fancy. They are not limited to Unix-like systems, even though the milter protocol was originally meant to extend only Sendmail.

In the case of inbox.com, it looks like they're using some software by MatriX ATC I have never heard of until today, and I have no idea what that particular MTA is capable of.

-Ralph