I have 2 Exchange server 2013 Std stand alone boxes in two separate forests managing mail for separate domains.
One works 100% the other has a problem with OOF auto replies. I have confirmed the automatic replies are enabled and set to ExternalLegacy. When I examine message logs for a sender I can see entries with EventId - MAILBOXRULE and the mail has a subject prefixed with "Automatic Reply:" but the auto reply mails are never sent \ delivered to either internal nor external contacts.
I have confirmed there is nothing on our firewall, both servers go through the same firewall. I have also confirmed the Smart Host we relay through does not have anything to do with it as both send connectors use the same smart host.
Only difference between servers is patch levels. Yup you guessed it, the fully patched up to date server has the issue? Checking now if I can roll back...
Any ideas and help would be greatly appreciated. Users are getting grumpy!