Customize "From" email address


Anyone know how to customize the “From” email address of Nagios?


edit your /etc/passwd file for the user nagios.
Modify or insert whatever you want in the 5th field. i.e.
vi /etc/passwd
nagios:x:502:502:[email protected]:/home/nagios/:/bin/bash


I’ve got the same issue, however I have what I want in the passwd file… just “Nagios”. All my pages show up [email protected] though. Any thoughts on how to modify what is sent out?


Yes, just do as I suggested. “vi /etc/passwd
nagios:x:502:502:[email protected]:/home/nagios/:/bin/bash"
I’ve tried it and it works. email’s now state “From [email protected]” Insteadof [email protected]


Sorry, should have been more clear. I meant I’d like to get rid of the @whatever on my pages. I was figuring I’d have to add something to the notification command or reformat it someway? The from address takes up 3 lines on my pager.


This is what I get in my From field "[email protected]"
But you might be referring to the subject field. If so, this is what I get in the subject field “** PROBLEM alert - FP CCI fpnd IO Virtual Server in AS400 Rm/Log_Layout8000_XML_file_processed is WARNING **”

And if so, then yes, it would take a few lines up on a pager.

Let us know which field, and we will see if we can help you out.


I already removed the subject field from my pages, that created a mess on the pager. Here’s my current command:

define command{
command_name notify-by-epager
command_line /usr/bin/printf “%b” “$NOTIFICATIONTYPE$\nHost: $HOSTNAME$\nService: $SERVICEDESC$\nState: $SERVICESTATE$\nInfo: $SERVICEOUTPUT$” | /bin/mail $CONTACTPAGER$

It’s just defaulting to the host name from the email… since one is not specified anywhere?


If you want the From to be just “nagios” and not "[email protected]" then do as instructed above.
Modify the 5th field and type in nagios.Like this:
vi /etc/passwd
I’ve tried it and it works. email’s now state “From nagios” Insteadof [email protected]"

Edited Mon Apr 04 2005, 08:30PM ]



Is what was already there. My email alerts say “Nagios [email protected]” But the pages just come up [email protected]

I appreciate your fast responses… I can’t seem to get this forum to load that fast. I was just happy to find a Nagios forum.


here are the steps I’ve taken and the output I get in an email.
/etc/passwd looks like this:
5th field is empty
I login as nagios
su - nagios
I send an email to a valid account.
/usr/bin/printf “%b” “***** Nagios *****” | /bin/mail -s “alert” [email protected]
This is what I get in the from field in the email.
From [email protected]

Now, I edit /etc/passwd and make it like this:
I now run the same command:
/usr/bin/printf “%b” “***** Nagios *****” | /bin/mail -s “alert” [email protected]
This is what I get in the from field in email:

But you say you already have only nagios in the 5th field?
Then what does your /etc/hosts file look like?
Mine is like this: localhost.localdomain localhost
xxx.xx.xx.xx tia2653

What is yours"


OK, perhaps you have configured sendmail to some method besides default.
What is the /etc/mail/ field that says "# my official domain name

… define this only if sendmail cannot automatically determine your domain

Ahh, wait a minute. That’s why mine says “from test” and not from "[email protected]" because my sendmail can’t determine my domain name? But that doesn’t make sense, since if I leave the 5th field blank in my /etc/password file, then I get “from [email protected]

Edited Mon Apr 04 2005, 09:12PM ]


try and edit the /etc/aliases file:
vi /etc/aliases

@(#)aliases 8.2 (Berkeley) 3/5/94

Aliases in this file will NOT be expanded in the header from

Mail, but WILL be visible over networks or from /bin/mail.

>>>>>>>>>> The program “newaliases” must be run after

>> NOTE >> this file is updated for any changes to

>>>>>>>>>> show through to sendmail.

nagios: nagios

Then run “newaliases”


Give Webmin a try, and use it to configure sendmail.

"If a local user tries to send email, sendmail will only allow the user to provide a different From: address if the user is on the list to the left. This restriction exists to prevent users from forging email with faked From: addresses origination from your system."
Quoted from “webmin” tool.
Edited Mon Apr 04 2005, 09:40PM ]


Well mail and sendmail are two different beasts… we even tried it manually just now through sendmail telling it From: and it still put the entire hostname in there. Then played with the host line, same thing. Tried the alias as well. I think I’m just gonna live with the long pages for now, and get back to it when it’s not such a chaotic day. Thanks man.


I worked on that all day, and I know for a fact, if I change position #5 in the /etc/passwd file to nagios, my mails from nagios only have “from nagios”, but can’t for the life of me explain why. It gave me a headache, so I had to quit, and really don’t have the drive to revisit the problem.


LOL, thanks for the valiant effort.