I have a problem in our environment, where message delivery is failing to Mail enabled PF with error code -
#554 5.4.6 Hop count exceeded - possible mail loop ##
Message delivery is same when sent to normal mail box. Mails are getting looped between HUB servers and this issue is happening for specifice site.
Environment - Exchange 2007 and 2010 co-existence
PF Server is on Exchange 2007