I'm getting this error on emails sent externally occassionally
There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.
<mail.(mydomain).org #5.5.0 smtp;550 Reverse DNS lookup failed for host 206.184.xxx.98.>
When I look up the reverse DNS info on 206.184.xxx.98 on www.dnsstuff.com
, I get the answer:
206.184.xxx.98 PTR record: mail.(mydomain).org. [TTL 43200s] [A=206.184.xxx.103] *ERROR* A record for mail.(mydomain)l.org. does not point back to original IP (A record may be cached).
I changed the A record for mail.(mydomain).com to 206.184.xxx.98 so that it would point back to original IP as the message suggests, but then no mail came in, so I had to change it back.
If it helps, I believe our Netscreen firewall has a public IP of 206.184.xxx.98 and then four VIPs which are 206.184.xxx.99, 100, 101, 103