Hi Wietse, Concerning #1, I checked the “mail.log” and I’m seeing the following warnings (many times):
postfix/smtpd[71979]: warning: hostname static.vdc.vn does not resolve to address 113.160.154.177 postfix/smtpd[72386]: warning: hostname bamovil-181-135-42-61.une.net.co does not resolve to address 181.135.42.61: nodename nor servname provided, or not known postfix/smtpd[16896]: warning: nwk-txn-msbadger0202.apple.com.dbl.spamhaus.org: RBL lookup error: Host or domain name not found. Name service error for name=nwk-txn-msbadger0202.apple.com.dbl.spamhaus.org type=A: Host not found, try again The second warning appears to be the most frequent. I assumed these were attempts from spammers to use the server as a relay. Concerning #2, I’ve asked my users to perform that test and I’ll get back to you with the results. I did run: sudo cat /var/log/mail.log | grep -c "connect from unknown” And I’m seeing 4794 occurrences since July 11th. Thanks, Chris McKinnon McKinnon Chris: > Hi, > > I'm experience performance issues with a Postfix installation I > setup on a Mac OS X server. Originally it was OS 10.7.4 and Postfix > 2.9.4, which worked very well. I was using a relatively stock Simple questions: (1) Have you looked at the system logfile for Postfix warning messages? There may be tons of them. (2) When you use the telnet command to connect from a client (that experiences the problem) to the Postfix server: $ telnet servername 25 How long does it take before Postfix responds with 220 servername ESMTP If (2) takes 5-10 seconds or more, Postfix may have a problem looking up the client hostname. A related symptom is that Postfix will log the connection as: postfix/smtpd[xxx] connect from unknown[ip.addr.ess.here] This assumes that you know where Postfix logging is stored. Fixing problems with hostname lookup requires someone who is familiar with MacOS. I'm sure there is at least one on this mailing list. Wietse