I have a server that runs postfix. I noticed recently that even though the service is running and doesn't report any errors, there are some issues with connections.
For example, curl localhost:25
hangs.
Comparing with other servers that work as expected, I narrowed the issue down to a process that is not running on the problematic server.
This process is missing:
postfix 30173 0.0 0.1 42780 5504 ? S 12:27 0:00 smtpd -n smtp -t inet -u -o stress= -s 2
From what I can tell, the configuration for both servers is identical so I don't understand why this process is not running on the problematic server.
What could be the reason why this process is not running?
All servers run Debian8.
EDIT
On the server with issues, command netstat -nlp|grep :25
generates output:
tcp 0 0 169.254.1.1:25 0.0.0.0:* LISTEN 323/master
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 323/master
Whilst on the server where postfix works, is outputs:
tcp 0 0 169.254.1.1:25 0.0.0.0:* LISTEN 15863/smtpd
tcp 0 0 127.0.0.1:25 0.0.0.0:* LISTEN 15863/smtpd
/etc/postfix/master.cf
# service type private unpriv chroot wakeup maxproc command + args
# (yes) (yes) (yes) (never) (100)
# ==========================================================================
smtp inet n - n - - smtpd
#628 inet n - n - - qmqpd
pickup fifo n - n 60 1 pickup
cleanup unix n - n - 0 cleanup
qmgr fifo n - n 300 1 qmgr
#qmgr fifo n - n 300 1 oqmgr
tlsmgr unix - - n 1000? 1 tlsmgr
rewrite unix - - n - - trivial-rewrite
bounce unix - - n - 0 bounce
defer unix - - n - 0 bounce
trace unix - - n - 0 bounce
verify unix - - n - 1 verify
flush unix n - n 1000? 0 flush
proxymap unix - - n - - proxymap
proxywrite unix - - n - 1 proxymap
smtp unix - - n - - smtp
# When relaying mail as backup MX, disable fallback_relay to avoid MX loops
relay unix - - n - - smtp
-o smtp_fallback_relay=
# -o smtp_helo_timeout=5 -o smtp_connect_timeout=5
showq unix n - n - - showq
error unix - - n - - error
retry unix - - n - - error
discard unix - - n - - discard
local unix - n n - - local
virtual unix - n n - - virtual
lmtp unix - - n - - lmtp
anvil unix - - n - 1 anvil
scache unix - - n - 1 scache