I'll start with the prefix warning that I've very unfamiliar with sendmail, I personally run and prefer postfix, but my new job uses sendmail for all their mailservers.
We have 3 sendmail servers, (1 primary and 2 that handle outgoing email) and one of them is not sending a FQDN during the HELO process. I've already searched and double checked against every solution I've seen posted so I'm hoping someone can suggest something I may have missed.
Here is what I'm seeing in remote logs when I test email.
Apr 21 11:27:13 nix postfix/smtpd: < gandalf.domain.com[xxx.xxx.xxx.xxx]: HELO gandalf
and I'm also seeing bounce back emails containing info like:
<<< 553 Bogus helo gandalf. <http://unblock.secureserver.net/?ip=>
When I telnet to the server in question port 25 I see the FQDN in the banner
220 gandalf.domain.com ESMTP Sendmail 8.13.8/8.12.11; Tue, 21 Apr 2009 11:20:59 -0700
and both uname -a and the hostname command show the FQDN
# Do not remove the following line, or various programs
# that require network functionality will fail.
127.0.0.1 gandalf.domain.com gandalf.domainukspellling.com gandalf localhost.localdomain localhost
#::1 localhost6.localdomain6 localhost6
xxx.xxx.xxx.xx gandalf.domain.com gandalf.domainukspelling.com gandalf
These settings are identical to two other sendmail servers and this is the only one not sending a FQDN in a helo statement. I'd greatly appreciate if anyone could tell me why this server is misbehaving as the primary sysadmin who is very familiar with sendmail is out this week.