Hi currently Nagios sends notifications from nagios@server.domain.com, How do I go about configuring this? Thanks


In a default Nagios install, it's also defined in the host-notify-by-mail or service-notify-by-mail commands, which you'll find in commands.cfg. The default would be something like:


So just add a -r sender@address option to the mail command, and that should work.

  • That's what I did, and it worked fine. Different alerts actually get sent out by different accounts because of our automated ticketing program. – breadly Oct 9 '09 at 17:25
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    I added this between /bin/mail and the -s – jgritty Nov 20 '14 at 0:50
  • @RainyRat - any chance you can edit your answer to place the -r as first parameter? - as other answers suggest then happy to upvote your answer :o) – Dazed Jun 12 at 16:13

Couldn't get the "-- -r nagios@domain.com" solution to work. It turns out options after "--" are options for sendmail. Looking at sendmail options, it should be "-fnagios@domain" NOTE NO SPACE between -f and nagios@domain.com.

So the following is now working :-

  command_line    /usr/bin/printf "%b" "Notification Type: $NOTIFICATIONTYPE$\n\nService: $SERVICEDESC$\nHost: $HOSTNAME$\Address: $HOSTADDRESS$\nState: $SERVICESTATE$\n\nDate/Time: $LONGDATETIME$\n\nAdditional Info:\n\n$LONGSERVICEOUTPUT$" | /bin/mail -s "$SERVICESTATE$ - Service Alert: $HOSTALIAS$/$SERVICEDESC$ is $SERVICESTATE$ **" $CONTACTEMAIL$ -- -fnagios@domain.com

Put -r nagios@domain before $CONTACTEMAIL$ on commands.cfg


What worked for me was adding -r $ADMINEMAIL$ before the -s (immediately after /bin/mail), and of course $ADMINEMAIL$ has to be set in nagios.cfg using the admin_email setting.


I was able to do this by changing the command to something liek:

command_line /usr/bin/printf "%b" "Notification Type: $NOTIFICATIONTYPE$\n\nService: $SERVICEDESC$\nHost: $HOSTNAME$\Address: $HOSTADDRESS$\nState: $SERVICESTATE$\n\nDate/Time: $LONGDATETIME$\n\nAdditional Info:\n\n$LONGSERVICEOUTPUT$" | /bin/mail -s "$SERVICESTATE$ - Service Alert: $HOSTALIAS$/$SERVICEDESC$ is $SERVICESTATE$ **" $CONTACTEMAIL$ -- -r $ADMINEMAIL$

The magic is the '-- -r' part.

ADMINEMAIL is set in your nagios.cfg, but could be any email address for the 'From' address.


None of the above works with current versions of Nagios and/or Postfix. The flag that needs to be added to the Nagios "host-notify-by-mail" or "service-notify-by-mail" commands in the file "commands.cfg" reads as follows:

-a "From: john.doe@uzh.ch"

Note that the quotation marks are essential!

  • This changes the From-address, but it does not change the Return-Path address. You may want to change both. – Christopher K. Jul 8 at 9:32

This is defined in etc/nagios3/conf.d/contacts_nagios2.cfg

You can define users with e-mails and groups. Also you can configure different groups for different purposes - e.g. web_admin for http alerts, admin for host alerts, etc.

  • In the contacts config, you configure the recipients of the mails sent, not the sender address. This question is about how to change the sender address ("where it sends mails from"). – Christopher K. Jul 8 at 9:27

For the bsd-mailx that my /usr/bin/mail command links to, nothing seemed to work, so I used /usr/sbin/sendmail (provided by postfix) like this:

command_line   /usr/bin/printf "%b" "Subject:** $NOTIFICATIONTYPE$ Host Alert: $HOSTNAME$ is $HOSTSTATE$ **\n\n**** Nagios *****\n\nNotification Type: $NOTIFICATIONTYPE$\nHost: $HOSTNAME$\nState: $HOSTSTATE$\nAddress: $HOSTADDRESS$\nInfo: $HOSTOUTPUT$\n\nDate/Time: $LONGDATETIME$\n" | /usr/sbin/sendmail -r "nagios@example.com" $CONTACTEMAIL$

For sendmail two things to consider:

  • Use -r to specify the return path (and from-address)
  • There is no -s for the subject. Instead, add the Subject: mail header in the printf followed by two newlines \n\n

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