I have a big problem with sending e-mails to gmail.
( echo Subject: test ; echo ; echo test ) | /usr/sbin/sendmail -Am -i -t -v user@gmail.com
Gives me error:
[2001:41d0:602:890::] The IP address sending this message does not have a PTR record setup. As a policy, Gmail does not accept messages from IPs with missing PTR records.
I have configured Reverse DNS on IPv6, but it seems like my server can't process it right.
My resolv.conf
nameserver 8.8.8.8
When I asked my server provider for help he told me that server won't answer on port 53 and it gets timeout on trying to get RevDNS.
So... what can I do to get it working? I tried so many things...