The device must be also linked to you.
Just as a suggestion to trace.... try to link the Notification directly to Device and test.
It works when linking to the device only.
OK. Just as next step, unlink from the Device and link to the Group. Restart traccar server and test again.
It seems restarting traccar after linking to the group made it work.... I am scratching my head now...
Probably it is related to this issue https://github.com/tananaev/traccar/pull/3710
Also my mistake, Device not obligatory be linked to you, you should have access to it at least via group.
It looks like it might be this indeed.
Thank you
@abyss
Could you check on mine? Or advise how to trace the issue?
As said formerly, I did it that way:
I have set up a new notification of "device online", checked "send via mail" and unchecked "all devices".
Then I created a group named "mail when online" and assigned it the former notification.
I did put one device in that group.