Maybe somebody like to merge the ssl-specific-parts back into actual emailer-local plugin. The "emailer-local-ssl" was a fork of the "emailer-local" plugin.
Update:
I activated the "Require Email Confirmation" checkbox in "ADMIN CONTROL PANEL > SETTINGS > USER". - Now the test-function works with the emailer-local plugin. I get the test mails. Even when i turn the checkbox off again. 
When open the "Emailer (local) Smtp SSL" in an new window...
...the forum gets down.
21/4 11:44 [8287] - [31merror[39m: SyntaxError: Invalid regular expression: /<!--[\s]*IF !(you're using an older commit, use type="text".)? Or pulling the up-to-date version would be even better ;)[\s]*-->([\s\S]*?)<!--[\s]*ENDIF !(you're using an older commit[\s]*-->/: Unmatched ')'
at new RegExp (<anonymous>)
at makeConditionalRegex (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:206:10)
at checkConditional (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:229:32)
at checkConditionals (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:225:27)
at parseValue (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:369:14)
at parse (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:390:17)
at cleanup (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:433:27)
at parse (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:400:15)
at parseTemplate (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:123:14)
at Object.templates.parse (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:109:11)
at /home/webservice/nodebb/node_modules/templates.js/lib/templates.js:157:30
SyntaxError: Invalid regular expression: /<!--[\s]*IF !(you're using an older commit, use type="text".)? Or pulling the up-to-date version would be even better ;)[\s]*-->([\s\S]*?)<!--[\s]*ENDIF !(you're using an older commit[\s]*-->/: Unmatched ')'
at new RegExp (<anonymous>)
at makeConditionalRegex (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:206:10)
at checkConditional (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:229:32)
at checkConditionals (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:225:27)
at parseValue (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:369:14)
at parse (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:390:17)
at cleanup (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:433:27)
at parse (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:400:15)
at parseTemplate (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:123:14)
at Object.templates.parse (/home/webservice/nodebb/node_modules/templates.js/lib/templates.js:109:11)
at /home/webservice/nodebb/node_modules/templates.js/lib/templates.js:157:30
21/4 11:44 [8287] - [32minfo[39m: [app] Shutdown (SIGTERM/SIGINT) Initialised.
21/4 11:44 [8287] - [32minfo[39m: [app] Database connection closed.
21/4 11:44 [8287] - [32minfo[39m: [app] Web server closed to connections.
21/4 11:44 [8287] - [32minfo[39m: [app] Shutdown complete.
[cluster] Child Process (8287) has exited (code: 1, signal: null)
[cluster] Spinning up another process...
And it restarts again.
@Hägar please check this pull request: https://github.com/erlgo/nodebb-plugin-emailer-ssl-smtp/pull/1
It tells you what has to be changed in template file to prevent that error.
Ouch. That's a funny bug. 
And that's the reason for this thread. If applied you get the settings-view of that plug-in.
The plugin itself doesn't work, but you can change the settings. So it's a first step. 
Thanks @ahwayakchih . Your hints helped to find a workaround.
https://community.nodebb.org/topic/4323/emailer-via-local-smtp-an-ssl-tls
Glad you found workaround. Still, its strange that you cannot use nodebb-plugin-emailer-ssl-smtp module (or the other one) alone.
The other one (emailer-local) "works", but only if the setup was made with this one (emailer-ssl-smtp).
I believe perhaps it has to do with the case, that they share the same settings in the database.
It probably help authors of those modules, or at least "emailer-local", if you could find what's different in settings in database. Maybe it's just a tiny option, that could be added to emailer-local and it would work in both cases?
Looking into both modules package.json and index.js it looks like https://github.com/NodeBB/nodebb-plugin-emailer-local/ does not install "nodemailer-smtp-transport" like https://github.com/erlgo/nodebb-plugin-emailer-ssl-smtp does by default. Maybe it was just a case of missing dependency?
As for sending mail, emailer-ssl-smtp adds secure: true when setting up transport, but that does not seem to be stored anyway, so shouldn't be used by emailer-local.
Also transport initialization is done a bit differently, but that too shouldn't matter because it's not "shared" in any way between modules.
I thought this must be just one line or one function. I stared at the code and the database, and didn't get what's the point of the matter.
Sorry. I just could reproduce it, but didn't know why it works that way.
