Hi everybody,

I've just spent the last few hours trying to configure Adapt Authoring's mail service using the local postfix configuration. So I'm writing this post just in case of what I found helps anyone. 

First, make sure your postfix is working (outside this post scope). In my case, I was relaying mail using Ionos (former 1&1) server. So it took me also a bit to figure that out.

AT uses nodemailer, but only uses a few possible parameters (have a look). If you're using gmail or similar well know smtp services, there is no big deal configuring it, but in my case I needed it to work with the local postfix.

Anyway, all things considered, this is what I learned:

1. First, you have choices other than the "Well Known" services. Diggin' in the net the best approach I found was using "smtps://user%40domain:pass@server/?pool=true". 
2. "Smtps" is not your only choice, you can use also use "smtps" and "direct". This last one was the one I had to use to configure my Postfix.
3. Pool=true is not the only possible parameter. If you don't intend to rewrite AT code, please have a look at this link, there are other possible parameters you may find useful: view
4. By default AT uses TLS security, i.e. you need a SSL Certificate to be able to send a mail; spoiler alert self signed certificates doesn't work. There is a way to prevent this without coding, just use one of the previous bullet parameters "ignoreTLS=true".
5. If you're planning to use mail to recover lost passwords, you need to set rootURL.

Just in case this is the configuration sniplet:

"useSmtp": true,
"fromAddress": "noreply@yourdomain.com",
"rootUrl":"http://adaptsaccessurl.com",
"useSmtpConnectionUrl": true,
"smtpConnectionUrl": "direct://localhost:25/?pool=true&ignoreTLS=true",

Hope this helps anyone.