@julian The problem is if I don't use npm then the plugins will be lost in the next deploy, since the server will clean and rebuild.

I just checked the plugin's commit history and it indeed shows an api change that will make it incompatible with 0.8.x branch(action:send.email has been changed to filter:send.email). So I guess the solution for me would be to stick to up to the commit where the api didn't change.

I'm running NodeBB 0.8.x with mongo backend on heroku

Tried with both sendgrid and mailgun plugin by installing them from from npm and configured them after deploying. But none of them register as email plugins( dashboard says email plugin not installed). None of them are able to send test emails either.

This shows up in the log for both(pasted only mailguns) of the plugins:
5/10 13:15 [72] - warn: [plugins/load] The following plugins may not be compatible with your version of NodeBB. This may cause unintended behaviour or crashing. In the event of an unresponsive NodeBB caused by this plugin, run `./nodebb reset -p PLUGINNAME` to disable it.  * nodebb-plugin-emailer-mailgun