Can anyone point me in the right direction or webpage? I have search on google
for this error, but they did not help.
Can you please post the rest of the information about the error (the
host it was associated with, usually something along the lines of "host
x.y.z[1.2.3.4] said: ..."?
If the host is not your own computer, the problem may not be directly
associated with your own server and user authentication, but rather with
another email server refusing to accept your server's emails. One
reason for this could be that the remote server is trying to do a
reverse DNS lookup of your domain/hostname that represents your server
and can't resolve it so it's rejecting your emails. Try the following
URL of someone who had a similar problem to this (scroll down and look
at page 2 & 3). What solved their problem was that they changed
something in a configuration file from their hostname to their IP
address, but they do not elaborate too much:
http://www.zimbra.com/forums/showthread.php?t=365
Cheers,
Daniel Hedlund
daniel@xxxxxxxxxxxx
