Hi. When i try to send a msg to sadc.int domain i get the following error:

################################################## #
This is the mail system at host server.domain.

I'm sorry to have to inform you that your message could not be delivered to
one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can delete your own
text from the attached returned message.

The mail system

<tcamela@sadc.int>: host mail.sadc.int[208.92.232.65] said: 554 5.7.1
<server.domain>: Helo command rejected: Host not found
(in
reply to RCPT TO command)
#################################################

What might be happening?

I already checked the XBL, SBL and RBL and my public IP and domain are not listed there.


micasrafael