It could also be due to the tinycon dependency see here
No email notifications after upgrade
I have upgraded to the latest nodebb master brunch and I have also updated the mailgun plugin, but mail notifications stopped working. Test email does not work too. Before upgrade it worked fine.
Ours does the same, that means it does nothing XD and I'm using the plugin emailer local... no idea what could be the problem and we need to use our mail server.
There was a change to the hook that emailers use, you can see the list of breaking changes here: https://community.nodebb.org/topic/6583/0-9-0-breaking-changes/2
It is likely the emailer needs to be updated, or if not your emailer will need to install the latest version directly from npm, and not via the plugins page.
NodeBBs on the
masterbranch will report their version as v0.8.2, even though that branch is going to eventially be v0.9.0.
@julian Thank you, mailgun from npm solved the problem.