I am using a Centos 6.5 machine as a mail server with sendmail as the MTA. I have a problem with a delay of sendmail presenting its banner so that the process of accepting e-mail can begin. The log files demonstrate as much as a 2 minute delay between the connection and the banner presentation.
#telnet Mail.DOMAIN.com 25 Connected to mail. Escape character is '^]'. < two minute delay before the next line is presented> h220 Mail.DOMAIN.com. ESMTP Sendmail 8.14.4/8.14.4; Sun, 23 Mar 2014 10:17:44 -0500
Log entries on the mail server for the above connection: Mar 23 10:16:05 Mail sendmail[31229]: NOQUEUE: connect from NAME.DOMAIN.com [10.0.0.187] Mar 23 10:17:44 Mail sendmail[31229]: AUTH: available mech=GSSAPI CRAM-MD5 DIGEST-MD5, allowed mech=EXTERNAL GSSAPI DIGEST-MD5 CRAM-MD5 LOGIN PLAIN
I have made the observation that if I put in the following line in the access file the 2 min delay goes away
Connect:10.0.0.187 RELAY
Obviously I can not set up a relay for every ip address, but this does solve the problem for internal network delivery of mail to the mail server.
I am using named for local dns service and have not been able to identify any errors or problems.
When I evaluate
nslookup NAME.DOMAIN.com 127.0.0.1 I appropriately get 10.0.0.187
So far I am stumped on this problem, if any of you have suggestions I would appreciate your help
Greg Ennis