2009/3/5 Ray <r...@stilltech.net>: > Server is live and fully functional. it deals with thousands of messages per > day and has for over a year. One user can't receive messages from one > contact. That contact doesn't even show up in the logs as spam or lost > connection or anything.
Can you clarify? I assume the recipient can receive mail from other senders just fine? Can you find out if another sender at the same domain can get mail to your user? > 1) have a message sent to another account on same server Good idea. > 2) "smtpd_delay_reject = yes" is set, so try to figure out sending ip address > and search for it in maillog. This is the default, but you'll still see records of the connecting IP address even if it's set to 'no'. Figuring out the sending IP address may or may not be difficult depending on the level of co-operation from the sender's side. > 3) get administrator of sending server to check his logs This will be the most productive; force them to *prove* that mail is leaving their servers, and ideally show that it's getting to yours. While you want to be helpful, you don't want to waste time. I wouldn't bother doing much more than grepping your logs without some confirmation the mail is approaching your systems. Also ask the sending user to send through a copy of whatever error messages they're getting back, it should be a bounce email. > 4) pcap during a communication attempt > > I'll do number 4 if It comes down to it, but frankly I've never done anything > with packet capture and it's a little intimidating. Chances are you'll find the problem well before you need to do this. On linux, right? tcpdump or wireshark/tshark is your friend :) Something like `tcpdump -n -i eth0 host rem.ote.ip.address and tcp port smtp
