Duh. Let me try to explain that again, this time in English. :)

I got mail lately, not forum messages. Twice. From people who hit the nice 'Email' button next to the forum messages, I should think. In those mails, it says that you can reply to them which leads people to think that, you know, you can. This used to work for me in the past. However, the last few times I get the above error messages and no dice. Understandable this time around?

To pinkyache: Nope, forum@forum.colemak.com doesn't work either it seems. And also, if that were the right adress it'd be a lie that you could answer by replying to the mail sent from forum@colemak.com wouldn't it? ;)

----- The following addresses had permanent fatal errors -----
<forum@colemak.com>
(reason: 550 ")
<forum@forum.colemak.com>
(reason: 550 )

----- Transcript of session follows -----
... while talking to colemak.com.:
>>> RCPT To:<forum@colemak.com>
<<< 550 "
550 5.1.1 <forum@colemak.com>... User unknown
... while talking to forum.colemak.com.:
>>> RCPT To:<forum@forum.colemak.com>
<<< 550 
550 5.1.1 <forum@forum.colemak.com>... User unknown

It almost looks as if the forum mailer expects to see a user name/ID/email and sees its own adress instead? Something wrong with the header field interpretation script? Or the handshaking procedure? I don't know these things well enough I'm afraid.

Hang on: When you compose forum mail to someone it says that you'll disclose your OWN email adress to the recipient! And when it says you can reply to the user by replying that means you should be replying to that person's email adress! Somehow, however, the mail gets sent from the forum mailer address instead of from the user address. It could be that email servers (or just my provider?) have become more clever at uncloaking emails sent by one adress on behalf of another in these spamming days?

Could anyone else try sending a forum email to themselves and see what address it gets sent from - the user address (as it should be) or forum@colemak.com?