Normally when someone sends you a message, Spamgourmet customizes the incoming's address to be:
From: "Sender's name - Sender's address" <reply address masking>
But if the sender's name looks like Before:This then Spamgourmet converts it to:
From: Before -
<reply address masking>
So as you can see:
- The sender's address is censored - I don't know who sent me this message!
- The part after the colon (the word This) is censored - it just looks weird
- A line break is added
My successful temporary solution was to add ^$ (blank sender in regex) as the exclusive sender.
P.S.
When inspecting such messages' full headers, you can find envelope-from <actual sender's address>, so at least there's a way to find the sender's actual address, but still not to use it as an exclusive sender.
In any case it's not ideal.
https://github.com/spamgourmet/spamgourmet/issues/55