Trying to send email to an outlook.com account and getting this failure. : Host or domain name not found. Name service error for name=outlook.com type=AAAA: Host not found Currently Microsoft doesn’t support IPv6 for hotmail.com, live.com or outlook.com. Postfix by default if IPv6 is enabled will attempt a IPv6 DNS lookup, the AAAA record, this ..
There’s a test available at http://cbl.abuseat.org/helocheck.html that will show you how the server is actually HELOing. For Qmail: # cat /var/qmail/control/me mail.fromthepa..
Changing postfix to qmail which will use the primary IP of the server (216.55.xxx.xxx) to send messages for all accounts is a great way to change the sending IP to one that is not blacklisted. Qmail default IP default mail ip in /var/qmail/control/..