Hi all. This is sort of like a follow-up on a problem I have with the same mailserver but now I have some new informations that could probably help someone an idea on what is going on. To recap, someone from Company A is complaining that they have not been receiving any emails sent from our mailserver. They have also said that we have been ignoring emails sent by them to our staff. Now, they are saying that they are receiving returned emails that says that their mailsever have encountered errors sending emails to our mailserver. I have checked our mail log and don't actually see any errors. Is there any way for me to find out what is going on and sort of investigate this further using any tools or something to make sure that our mailserver are working fine. At this point, we are just pointing blame to each other's mailserver. A different question. If we were to create a new mailserver, is there an easy way to migrate all the users and emails from our old mailserver to the new mailserver? FYI, the current mailserver is setup using the guide in this site, ie. "Virtual Users With Postfix, PostfixAdmin, Courier, Mailscanner, ClamAV On CentOS". However, the current mailserver is running on FC5.
Follow-up I have just checked the maillog for the past 2 days and this is what I found in regards to their email from their mailserver. After a few lines, I get this in the logs I am not sure if this is related but after the first few entries, there is some errors about the RBL Lookup Hope that is helpful in sorting out my issue
OK. Another update. I've really looked into our mailserver log and seen several of these RBL lookup errors, mostly affected the following :- sbl-xbl.spamhaus.org opm.blitzed.org I've noticed that before losing connecting from their mailserver, there was always a RBL lookup error, with their reversed IP Could this be the reason for the failed email delivery? Is there a way to correct this RBL lookup error?
What's in /etc/postfix/main.cf? Please check that your server isn't blacklisted: http://www.mxtoolbox.com/blacklists.aspx
Basically what happened was that whenever the remote mailserver tried to connect to the local mailserver, there was a RBL lookup error. This only happens with opm.blitzed.org and sbl-xbl.spamhaus.org. Because of that RBL lookup error, the connection was terminated. I have removed the 2 RBL server from main.cf. As far as I know from surfing the net, opm.blitzed.org is no longer active, while spamhaus.org have changed it to zen.spamhaus.org. However, I am still getting RBL lookup error with zen.spamhaus.org, so I have removed that from main.cf too. Anyone have these RBL lookup errors with zen.spamhaus.org? What causes this lookup errors and is there any alternative spamhaus server that I can use that won't cause these RBL lookup errors. Thanks again.
I don't think the IP of the remote server is blacklisted. I've checked against Spamhaus IP Address Lookup on their website and it is not listed. Why would a blacklisted IP caused a RBL lookup error? How do you use spamhaus's spamfilter server, ie. zen.spamhaus.org? Before I removed that entry from postfix's main.cf. Below is a clip from my main.cf I don't have any issues with the other RBL servers, but with the above configurations, occasionally I get RBL lookup errors with zen.spamhaus.org. As you can see, the IP of the remote mailserver connected above is 213.192.61.11, which is not blacklisted on any of the Spamhaus's lists. Anyone have any idea what is wrong? Do I need to configure something to make my mailserver work with Spamhaus's server? ie. zen.spamhaus.org. Thanks again.
