I’ve installed Stephane’s zabbix template to monitor my nethserver postfix. My Nethserver mail is working properly but my Zabbix has an alert on my nethserver saying “SMTP service is down on Nethserver” .
Looking at my Nethserver Postfix servoces I have the followingTCP TCP ports listed 25, 465, 587.
So I looked into the template I’ve uploaded from stephdl repo - Template App Postfix for NethServer and I checked the Zabbix Expression for “SMTP service is down on {HOST.NAME}”. The Epression is as follows:
I’m checking 465 as this is the port thats important for my external mail. Do you see anything wrong with this expression?
Should I be checking only port 25? And is there a way to expand this expression check to check both 25 and 465?
SMTP is used for several “things” among the mail transports.
On port 25, it accepts email from other servers.
On port 587, it accepts from server authorized users messages to deliver to self or other servers.On port 465, it accepts encrypted from server authorized users messages to deliver to self or other servers.
But all these ports may be or may be not listening on the same interfaces… So… IMVHO you should take a read on documentation and firewall for create the correct expressions for SMTP monitoring…