Mailbox unavailable. The server response was: 5.7.1 Client does not have permission to send as this sender

Filed in .Net Leave a comment

I got this error when I am trying to send mail using System.Net.Mail. I got this error because our exchange server does not relay those emails in which From Address and Reply To Address are different. I have a requirement that both need to be different, for this network administrator must need to allow this thing in exchange server.

TOP