Steps to reproduce the issue

In the global config, in test mail button i'm getting test mail ok even if the SMTP mail server or port domain is clearly wrong (doesn't exist).

Expected result

Use SMTP. and give an error when the server does not send the mail.

Actual result

Always The email was sent successfully to user@example.com using SMTP. You should check that you've received the test email.
MEssage ok, because it's using sendmail, not SMTP.

System information (as much as possible)

3.5.x

Additional comments

Only happens in the test mail in the global config, all other mail functions seem to work fine.