Gmail Messages Bouncing: Exchange 2007- 550 mailbox unavailable (state 18)
Posted on 2011-09-19
Microsoft Exchange 2007 SP1
TrendMicro Worry Free Advanced (Spam Filtering)
HughesNet Satellite ISP
Problem: Messages sent from Gmail, etc are receving:
Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the recipient domain. We recommend contacting the other email provider for further information about the cause of this error. The error that the other server returned was: 550 550 Requested action not taken: mailbox unavailable (state 18).
Exchange sends fine , and receives some mail correctly (nothing in the Que - Watchguard routing correctly)
MXToolbox shows MX record correctly knows hostname
MXToolbox shows no blacklist issues
TestExchangeConnectivity.com shows everything working correctly.
Nothing in the Trend Quarantine or logs
Hughesnet has indicated that it will NOT create a PTR record for my static IP.
Seems as though the message is getting rejected early in the process...
A. What is the problem?
B. How can I remedy this?