Where are the logs?
The default location depends on your linux/unix system, but the most common places are
- /var/log/maillog
- /var/log/mail.log
- /var/adm/maillog
- /var/adm/syslog/mail.log
If it's not there, look up /etc/syslog.conf. You should see something like this
mail.* -/var/log/maillog
sendmail writes logs to the mail facility of syslog. Therefore, which file it gets written to depends on how syslog was configured.
If you system uses syslog-ng (instead of the more "traditional" syslog), then you'll have to look up your syslog-ng.conf file. You'll should something like this:
# This files are the log come from the mail subsystem.
#
destination mail { file("/var/log/mail.log"); };
destination maillog { file("/var/log/maillog"); };
destination mailinfo { file("/var/log/mail.info"); };
destination mailwarn { file("/var/log/mail.warn"); };
destination mailerr { file("/var/log/mail.err"); };
Unable to send out emails?
One of the most common reason I've seen for a freshly installed sendmail not being able to send out emails is the DAEMON_OPTIONS being set to listen only on 127.0.0.1
See /etc/mail/sendmail.mc
dnl #
dnl # The following causes sendmail to only listen on the IPv4 loopback address
dnl # 127.0.0.1 and not on any other network devices. Remove the loopback
dnl # address restriction to accept email from the internet or intranet.
dnl #
DAEMON_OPTIONS(`Port=smtp,Addr=127.0.0.1, Name=MTA')dnl
If that's your case, remove the "Addr=127.0.0.1" part, rebuild your conf file and you're good to go!
DAEMON_OPTIONS(`Port=smtp, Name=MTA')dnl
[root@server]$ m4 sendmail.mc > /etc/sendmail.cf
[root@server]$/etc/init.d/sendmail restart
If you've been making changes to /etc/sendmail.cf manually thus far (instead of the *.m4 file) you can make similar changes in /etc/sendmail.cf. The offending line will look like this:
O DaemonPortOptions=Port=smtp,Addr=127.0.0.1, Name=MTA
Change it to:
O DaemonPortOptions=Port=smtp, Name=MTA
Kyle,
** I'm by no means a sendmail expert **
In your use case, the need for sendmail to accept / queue up the messages asap is key(batch processing?). If you haven't, take a look at sendmail options: QueueLA and RefuseLA - Queue Load Average and Refuse Load Average. If you are really bombarding sendmail your load averages will go through the roof quickly and you'll hit RefuseLA which might be part of your timeout issue. You may want to increase RefuseLA (if you haven't already).
To keep sendmail from doing too much at once (receiving and transmitting) lower your QueueLA. A lower value of QueueLA will put sendmail into queue only mode so sendmail will focus on queuing work and save the transmit / sending work for later. A low QueueLA and high RefuseLA will result in the system queueing up large amounts of mail(disk space) then begin sending it out after the load falls below QueueLA.
For normal sendmail configs it is worth noting that QueueLA should not be much lower than RefuseLA, and possibly it should be very slightly higher.
Delivery mode 'q' is an extreme version of a low QueueLA setting, where you'd have to somehow initiate a delivery command to begin outbound message transfer.
Resource:
http://www.brandonhutchinson.com/QueueLA_and_RefuseLA.html
Best Answer
From:orConnect:instead of plain IP addresses or domains, so as not to have to think whether the rule is about the domain name of the host that connects to your host, or the domain name of the sender's address (they are not necessarily the same).