Sendmail ‘collect: premature EOM: unexpected close’

Sendmail 

‘collect: premature EOM: unexpected close’

If you are getting a ‘collect: premature EOM: unexpected close’ in your mail logs, or if you have people complaining that they cannot send email to your server and you have this error, then there's a solution to the problem.

I had over time installed several Blacklist denials in my sendmail.mc config file, and that perhaps one of these was not responding anymore.

By commenting out each Blacklist deny one at a time, I discovered which one was no longer responding. To comment out a line in the main sendmail.mc file, simply put dnl at the start of the line. 

FEATURE(`dnsbl’,`sbl-xbl.spamhaus.org’,`“550 Denied RBL ” $&{client_addr} ” by sbl-xbl.spamhaus.org”’)dnl

FEATURE(`dnsbl',`dnsbl.sorbs.net',`"554 Rejected " $&{client_addr} " Found in dnsbl.sorbs.net"',`t')dnl