I tried to find some info about that but everything I found is in regards to self hosted version.
As we are having problems with email delivery with basic cloud setup I would like to link our own SMTP, I see no such possibility in admin menu, Can you please guide me in that matter,
You need to log into your discourse instance and change it in the config called app.yml
Once changed you need to rebuild your discourse app.
If you are hosted by Discourse.org then you should email support. If you are having trouble with mail delivery, you can let them know. I believe that to customize the SMTP settings you need to be on the Enterprise plan.