SMTP server without SSL support cannot be used?

[depay]

Then I tried a SSL supported server, and it works.
I've seen some comments in util/mail.go like: go doesn't support plain auth . Does it have any relation with the problem?

[crspeller]

Correct. The go library we are using for smtp support does not allow credentials to be transmitted in cleartext. Therefore SMTP servers without SSL support can not be used.

[depay]

thanks! @crspeller