Originally in 964da21817
we hid the SMTPAuthenticationError message except in
very specific cases. However this message often contains
helpful information from the mail provider, for example
here is a response from Office365:
> 535 5.7.139 Authentication unsuccessful, user is locked by your
organization's security defaults policy. Contact your administrator.
So, we will show the error message in the modal UI instead
of supressing it with a generic message to be more helpful.
00608a19c6