I've had mail bounce back to me from verizonwireless recently. I telnet-ed to their mail host and got the following message. I've checked senderbase.org and it does not state that we are on any restricted lists. So it must be our MTA perhaps? Does anybody know what settings I need to change on Exchange 2003 SP1 (running on Server 2003 R2) to clear this up? I assume we're having trouble with other mail domains too but I can personally confirm this one at this time.
554-Your access to the VZW mail systems has been rejected due to the sending MTA
or Network Service Provider's poor reputation / e-mail hygiene on the Internet
554-Please reference the following URL for more information:
554 If you believe that this failure is in error, please contact the recipient v
ia alternate means.
Connection to host lost.
Thanks in advance.