Notification emails not sent


I’m stumped with a problem that has cropped up wtih Nagios.
I have a Nagios server that monitors quite a lot of systems. It has been in place and running for 6 months and up until 2 weeks ago would send email to the proper users as desired.
Whenever I make any changes to the config files, I back them up before making those changes so I can go back in time and easily undo any changes made.
The only things I’ve changed on the Nagios box in the past few months have been those config files.
So, up until two weeks ago, everything was working well.

Nagios email notifications are no longer getting out.
Nagios is logging that it sends out those emails.

I’ve also used Wireshark to view smtp traffic out of the Nagios box. I can see Nagios opening a smtp connection to the Exchange server and quitting without any real data sent, packet sequence below:
7151 (from nagios) (to Exchange) SMTP: Command: Helo linux
7152 (from Exchange) (to Nagios) SMTP: Response: 250 (Exchange server) Hello
7153 (from nagios) (to Exhcnage) SMTP: Command: QUIT
I would think there should be some additional packets between 7152 and 7153 that include recipeients, from and the data for the email.

I’ve even restored all nagios config files in the /nagios/etc folder that have changed in the last three months to the state they were in 3 months ago.

It can’t be a problem with the config files. I’m currently trying to find out how the email is being created and sent the the Exchange server. Any help would be appreciated. I’ve read through the manual, and either I’m not getting how this is happening, besides the settings in the config files, or not seeing it, or something.



check your notify-host-by-email and notify-service-by-email commands and try to run them directly from shell with some fake strings instead of macros