I have a working https://www.npmjs.com/package/nodebb-plugin-emailer-ssl-smtp plugin on NodeBB 0.7.x-dev on OpenShift.
I'm not sure if it's the same problem, but in my case, plugin (or, to be more exact, part of node.js internals) could not verify SMTP server's certificate.
Adding following line, somewhere at the head of
nodebb-plugin-emailer-ssl-smtp/index.js should help in such case, but please keep in mind, that it makes sending mails (and any outgoing connections made from the application) unsecure:
process.env['NODE_TLS_REJECT_UNAUTHORIZED'] = '0';
Which means, it should be done ONLY for testing.
If you would like to get a better error report from the plugin, you can try to modify line 48 of
nodebb-plugin-emailer-ssl-smtp/index.js file, to look like this:
winston.warn('[emailer.smtp] Unable to send `' + data.template + '` email to uid ' + data.uid + '!!', err);
That should output full error data from node.js to your logs/console, which should help to find out why the plugin could not send e-mail.