I have a little problem with my courier MDA. One of my users wants to send this mail via his outlook.com MTA but as he has registers his domain and mail address on my server, my sever rejects his mails whenever they arrived over the different MTA. How can I let courier accept mails from this different source?
Hope I explained it right... and somebody has a hint for me.
Got an email from my blacklist-monitoring service with the following content:
Various sorts of open proxies. An open proxy is generally a web server that allows email sending to piggyback on a script that sends email.
Dedicated Spam BOTs used to send spam.
Worms/viruses that do their own direct mail transmission.
Trojan-horse or "stealth" spamware.
Did anyone else ever experience this?
Checked the log-files but cant find any unusual activities. Could it be that the spam is sent out "under the radar" not loged in the logfiles?
How can I check if the webserver is an open proxy?
Here some good blacklists for spam-filtering with postfix.
In postfix?s main.cf put under section smtpd_recipient_restrictions:
==> Moved to byteworkshosting issue #4 on GitHub.