Tag Archives: Postfix

Monitoring Postfix in Zabbix

First, configure the Zabbix agent.

Create a file (in the nano editor, press Ctrl+X to exit, and y/n to save or discard changes):

nano /etc/zabbix/zabbix_agentd.d/userparameter_postfix.conf

Add to it:

UserParameter=postfix.maildrop, find /var/spool/postfix/maildrop -type f | wc -l
UserParameter=postfix.deferred, find /var/spool/postfix/deferred -type f | wc -l
UserParameter=postfix.incoming, find /var/spool/postfix/incoming -type f | wc -l
UserParameter=postfix.active, find /var/spool/postfix/active -type f | wc -l
UserParameter=postfix.queue, mailq | grep -v "Mail queue is empty" | grep -c '^[0-9A-Z]'

Alternatively, you can simply add the lines above to the Zabbix agent configuration file.

Also open the Zabbix agent configuration file:

nano /etc/zabbix/zabbix_agentd.conf

We will allow Zabbix agent to work as root with the user specifying:

AllowRoot=1

Restart the Zabbix agent to apply the changes:

sudo /etc/init.d/zabbix-agent restart

Now go to the Zabbix server.
Create a Postfix template, add data items to it, specifying the type – Zabbix agent, and the keys: postfix.maildrop, postfix.deferred, postfix.incoming, postfix.active, postfix.queue.
Create graphics for the created data items.

You can also create a data item that counts the number of Postfix processes by specifying the type – Zabbix agent, and the key:

proc.num[,postfix]

Also create a trigger that tells when processes 0.

Download the ready template here – Zabbix шаблон для Postfix

How to enable SMTP without SSL on port 25 in iRedMail / Postfix

To allow the sending of messages on the mail server without encryption via port 25, you need to open the Postfix configuration file, for example, in the nano editor (in which Ctrl+X to exit, y/n to save or cancel changes):

sudo nano /etc/postfix/main.cf

And uncomment two lines:

smtpd_sasl_auth_enable = yes
smtpd_sasl_security_options = noanonymous

And leave the commented line:

#smtpd_tls_auth_only=yes

Reload Postfix to apply the changes:

sudo service postfix restart

After that it will be possible to send messages via SMTP through port 25 without SSL, and as usual through 587 with SSL.

See also:
Allow insecure connections to POP3 / IMAP iRedMail

How to fix error “host NAME greeted me with my own hostname NAME”

I noticed once on one server that Postfix does not always send mail, the logs had the following error:

warning: host NAME[192.168.5.5]:25 greeted me with my own hostname NAME

After seeing the host name:

hostname -f

Found that it is not correct and coincides with that on which the mail is sent!

Changed the host name to the correct one in the following files (in the nano editor Ctrl+X to exit, y/n to save or cancel changes):

sudo nano /etc/hostname
sudo nano /etc/postfix/main.cf
sudo nano /etc/hosts

Done, after that the error did not appear and the mail was successfully delivered.