Nagios Support Forum

That's because you do not have the "mail" package installed. Your task is not to figure out a replacement for postfix, your task is to figure out why you can't connect to the mail server you are trying to send to.

Unless the mail server you are trying to send to is your own Nagios server. You still haven't said who owns the mail server: your organization or someone else?

I presume the removal of postfix has now left your server without an mta.

Its working after changing the sendmail.mc and putting mail server at

define(`SMART_HOST', [IP ADDRESS])dnl

Okay, so you switched from postfix to sendmail correctly and you are now receiving notifications correctly?

Yes I do

Thanks for the help. Good to close