Sender is not authorized by default message

0 votes
asked Sep 7, 2014 by Maxim Terletsky (120 points)
edited Sep 8, 2014

Hi guys, I get the following message "Sender is not authorized by default to use ‘’ …" when I put ‘’ into the Sender filed and the message ends in a Spam folder for some of my clients (not all of them). Any advice on the subject? (MyCompany would be something real, of course). It's probably some configuration but I want to check here first. The message is sent using Rebex.Net.Smtp.Send.

Applies to: Rebex Secure Mail

1 Answer

0 votes
answered Sep 8, 2014 by Tomas Knopp (58,890 points)
edited Sep 8, 2014

Hi Maxim,

the error message suggests that you are trying to send the email as a different sender than the one which owns the mailbox (e.g. ''). Could you please check on that?

If you are sure that you should really be able to send through the 'mail-service' account with a different sender, then it is a matter of configuring the SMTP server in a right way to allow this as it depends on the SMTP server whether it will accept message with a 'different' sender or not.