Friday 4 September 2015

SMTP: Err Msg: 503 Bad Command Sequence

Initially i was stuck with the email problem, where i was getting mail sending failure. But i resolved the issue by appropriate SMTP configuration. Then what i found that there was a different error response i was getting when i was sending email through localhost IIS server 2012.

"Bad sequence of commands. The server response was: This mail server requires authentication when attempting to send to a non-local e-mail address. Please check your mail client settings or contact your administrator to verify that the domain or address is defined for this server."

All was well, the fault was enable localhost SMTP setting in IIS Application level. I did it and it worked for me. You may try as given in snap:

Once you changed the setting, try to send mail again. Should work.
If not you can investigate further like given below