When you Mark unavailability in a techinician A, and setup a backup and click "Assign to following technician B", and i have a business rule that say "if subject say "xxxx", then assign this request to technician A.

So, with the Backup technician setup ON, all request are assigned to the technician B, but this works only when i add a new request by the self service portal, and don't works when a new request is created by email. 

Please Help