This is the message I am receiving from our user who is remote.
The sender indicates that he can reach no one in my domain - but it seems to be him. Any suggestions?
Technical details of permanent failure:
Google tried to deliver your message, but it was rejected by the server for the recipient domain outbounds9.obsmtp.com by outbounds9.obsmtp.com.
The error that the other server returned was:
550 permanent failure for one or more recipients (email@example.com:quarantined)