I have problem with server based on Debian and Plesk. Somehow i have blocked my IP.
In IPTables i have only two lines with my IP (whitelist):
0 0 ACCEPT udp -- * * .......MyIP........ 0.0.0.0/0...
Anybody can help? I think this is problem in headers configuration forwarding machine. In the mail is given the original sender, but with my server IP. I don't now what i must reconfigure and how?
Thx for replies. I think my problem is similiar, but occurs not when some person sent mail. I have errors only when i set forwarding to external email in in e-mail setings in plesk panel (domains -> emails).
Sorry for my english.
When i enable forwarding in mails configuration panel in Plesk and add address from external domain, then i got mail delivery failure. For mails from my own domain all is OK.
How fix that problem without losing security?
I have Postfix with Dovecot