I have exchange 2010 and smtp server IMSS. I have a problem with one mail. The user send a mail to one customer and it got bounced back with error msg.
Your message wasn't delivered due to a permission or security issue. It may have been rejected by a moderator, the address
may only accept e-mail from certain senders, or another restriction may be preventing delivery.
The following organization rejected your message: smtp.secureserver.net.
It is not only to one customer, if we send this particular mail to any domain, gmail, yahoo, rediff, we will get same bounce back msg.
Then we changed the Public IP of SMTP server with another which we had. From there it goes fine.
So what may be the issue. only one mail not going to any domain with one particular public IP. All other mails going to all domain with same public IP