Re: [Zabbix-users] Zabbix 5.4 email alerts and SMTP configuration

[Guus S. <gsn...@gm...>]

Op di 17 mei 2022 08:06 schreef Jeff Cold <sc...@un...>:

>
> "We use Zabbix 5.4 inside a VPN.  We have our own Postfix email server
> inside that VPN that forwards email to a campus email server outside
> the VPN.  To do aliasing we've set up a bogus domain recognized by our
> Postfix server different from the proper domain in the SMTP helo field
> in Zabbix.  Sending email to alert@[bogus_domain] gets resolved and works
> from the CLI.  Sending email based on an event from Zabbix, gets rejected
> by the campus email server because the SMTP helo domain and bogus_domain do
> not match.  Has anyone tried something similar and had it work?"
>

Apologies first: I haven't tried this for myself.

It appears that your Zabbix server tries to deliver the alert mails
directly to your campus mail server, instead of your postfix server.

I see 2 options, both in your Zabbix config
- let Zabbix to use your postfix server (instead of direct delivery)
- fix the SMTP helo for Zabbix (so direct delivery works, even when postfix
is down)

Another option would be to have the Campus mailserver to whitelist the
zabbix server, but that's probably the harder way :).

An even better option: use authenticated SMTP (submission). The Campus
mailserver will be a lot more cooperative :).
You'd still need to watch the sender mailbox for errors and bounces, though.


Mvg, Guus Snijders