Email alerts not working in the docker container

[gs2527]

I have LibreNMS running in a docker container, I have tried to send email alerts using mail and sendmail but it doesn’t seem to work.

Mail option triggers the below error :
Could not issue critical alert for rule ‘Sensor over limit - Check Device Health Settings’ to transport ‘mail’ Error: Could not instantiate mail function.

sendmail option triggers this :
Could not issue critical alert for rule ‘Sensor over limit - Check Device Health Settings’ to transport ‘mail’ Error: Could not execute: /usr/sbin/sendmail

f0bec5c2b0a7:/opt/librenms$ ./validate.php

Component	Version
LibreNMS	21.12.0
DB Schema	2021_25_01_0129_isis_adjacencies_nullable (229)
PHP	7.4.26
Python	3.9.5
MySQL	10.5.13-MariaDB-1:10.5.13+maria~focal
RRDTool	1.7.2
SNMP	5.9
====================================

[OK] Installed from package; no Composer required
[WARN] You have the old alerting system enabled - this is to be deprecated on the 1st of June 2015: Redirecting to Google Groups
[OK] Database connection successful
[OK] Database schema correct
[WARN] IPv6 is disabled on your server, you will not be able to add IPv6 devices.
[WARN] Non-git install, updates are manual or from package

Any help would be appreciated!

[Kevin_Krumm]

what do you have configured to send mail? l

[gs2527]

Please see the settings, the email address file isn’t empty, I just removed it for the screenshot.
When I go to alert transports and try to test sending an email I get these errors.

[wuselzwusel]

I am having the exact same issue running the latest docker images.
In global config I entered the information required (“from name” and “from email address”).
I tried both “mail” and “sendmail” as a transport but “sendmail” cannot work because the binary doesn’t even exist in the docker container.
In the alert transport I chose “Mail” as transport type and I put in the email address which the mail is sent to - or is that wrong?

In any case, Transports - LibreNMS Docs is also not really telling me much how to configure it.
It would be great if someone could make an example how to do configure mail in the docker container setup. Or how to debug it.

[wuselzwusel]

So no one is running librenms with docker and wants to get emails from the system?