i have a serious problem receiving emails from xxx.gr. The error message as is written below is 4.7.1 and of course i cannot receive any email from xxx.
Oct 24 15:41:24 mail postfix/smtpd: NOQUEUE: reject: RCPT from unknown[10.5.225.10]: 450 4.7.1 Client host rejected: cannot find your hostname, [10.5.225.10]; email@example.com firstname.lastname@example.org proto=ESMTP helo=<mailhost.xxx.gr>
Unfortunately i cannot have a reverse lookup for the specified ip so i added that to access.cidr file, as i already made for other IPs, but i still cannot accept messages from xxx.gr. I also tried to add 10.5.255.10 mailhost.xxx.gr to the hosts file.
Do you have any idea why the problem persist?