The problem is that the mails that the app sends are very rarely delivered to hotmail/outlook, apparently I can send 1 mail per day, but not sure if is a coincidence (the app is simplified to test purposes, I have a test action that the only thing does is send the mail and ensure to catch and show any error). No error is thrown. Obviously I checked the spam folder and rules on the destination.
But I configured that same account (info@*******.com) on desktop client (thunderbird) following the configuration instructions on the workspaces console. And using that client the mail delivers almost instantly and without any limit/problem to outlook/hotmail.
What is happening? the only difference is the SMTP server used in both cases, but inside the app I cannot use the same SMTP server that on desktop client because it rejecting to connect to it from the hosted app (apparently a intentional restriction).