Banned by bluewin.ch
Since Tuesday evening I cannot send mail to bluewin.ch (one of the leading providers here) from codeconsult.ch anymore, apparently they blocked my server for some (probably spam-related) reason.
I found a workaround using another SMTP server, but this is weird: incoming spam can be killed fairly easily, but if providers start blocking incoming domains or IP blocks based on spam that they received with fake mail headers we're in trouble.
Connectivity going down. Now the hard part is finding who to contact, the bluewin site is not exactly rife with technical contact information.
Update #1: I'm trying the WHOIS technical contact for bluewin.ch, it will be interesting to see if someone answers...
Update #2: Funny, bluewin seems to have the same problem with other providers sometimes. I haven't gotten any answer from them yet but I'm not giving up!
Update #3: No human response yet (I'm not counting on it after four days), but the ban has been lifted, my server is not blocked anymore.