A method for processing email for a multi-tenant database system is presented here. The system includes a plurality of data centers and a plurality of instances of a database system core. Each data center implements at least one instance of the database core. The method receives an incoming email at a first local mail transfer agent (MTA) of a first data center, wherein the incoming email is erroneously directed to a first instance of the database system core. The method continues by searching a private domain name service (DNS) database maintained at the first data center, based on an identifier of the first instance and an identifier of the first data center. The method then obtains an identifier associated with a second data center of the plurality of data centers, and routes the incoming email in accordance with the identifier of the second data center.