Symptoms

QMail is not working after the upgrade. Qmail service appears to be running on all qmail boxes but connections to port 25 on the load balancer are refused.

The load balancer is probing on port 3100, which seems to be down. Therefore the loadbalancer sees the mailservers as down.

Cause

Service SpamAssassin proxy fails to start:

# service sa-proxy start
Starting.../etc/init.d/sa-proxy: Usage: daemon [+/-nicelevel] {program}
# service sa-proxy status
sa-proxy is stopped

Resolution

Issue appeared because of an error in init script of service:

[root@pemlinmail01 ~]# diff /etc/init.d/sa-proxy /etc/init.d/sa-proxy.bak
28c28
<       daemon --user  $QMAIL_USER $SAPROXY 3100
---
>       daemon --pidfile $PID_FILE --user $QMAIL_USER $SAPROXY 3100

After this change was applied service was started, and mail was accessible.

Internal content