Nagios Support Forum

Hello

I have recently installed nagios and have configured hosts to be monitored. Everything is now working except email notifications are not going through. I have limited experience with Linux and this is my first attempt with Nagios as well.

I am on CentOS 6.3 and am trying to get Postfix to send email using my exchange server for smtp.

I have made configuration changes to /etc/postfix/main.cf that look like this:

mail_owner = postfix
myhostname = mail.domainname.com
mydomain = domainname.com
myorigin = $myhostname
inet_interfaces = all
mydestination = localhost, localhost.domainname.com
mynetworks = 10.x.0.0/16, 127.0.0.0/8
home_mailbox = Maildir/

- I can use mail command on the server to send email to local accounts (ie, root, nagios) ... no problem
- I have verified that my my CentOS box is able to telnet to my exchange on port 25 ... no problem

However, Nagios is not able to send out email. So I tried it with mail command to send email to my exchange email address. This is what shows in my maillog file

Nov 28 23:13:39 CentOSServerName postfix/smtp[10188]: connect to domainname.com[10.x.x.x]:25: Connection timed out (my dns/ad server ip)
Nov 28 23:13:39 CentOSServerName postfix/smtp[10189]: connect to domainname.com[10.x.x.x]:25: Connection timed out (my dns/ad server ip)
Nov 28 23:13:39 CentOSServerName postfix/smtp[10189]: connect to domainname.com[10.x.x.x]:25: Connection refused (my second dns/ad server ip)
Nov 28 23:13:39 CentOSServerName postfix/smtp[10189]: connect to domainname.com[10.x.x.x]:25: Connection refused (my third dns/ad server ip)
Nov 28 23:13:39 CentOSServerName postfix/smtp[10188]: B4C1E809BB: to=<myemail@domainname.com>, relay=none, delay=23723, delays=23693/0.02/30/0, dsn=4.4.1, status=deferred (connect to domainname.com[10.x.x.x]:25: Connection timed out)

From the logs it appears that Postfix is trying to send email using my dns/ad server instead of mail server that I mentioned in the main.cf file! How can I force it to use correct server to send out emails? I must have overlooked something.

I would really appreciate if someone can identify the disconnect here.

Many Thanks!

Hi

Just to update that the issue is resolved. I needed relayhost entry and had to correct my hostname!

Glad you got it resolved!