In a multi-tenanted Exchange 2010 installation is it possible to route to different send connectors for different organizations

Solution 1:

Out of the box, the answer to this is no... although you can compile your own, or there are third party add-ons that will allow for sender-based routing.

Self-Compiled Example:

http://windowsshare.wordpress.com/2010/06/11/configure-sender-based-routing-in-exchange-2007

Third-Party:

http://www.messageconcept.net/en/products/exsbr/

http://ivasoft.com/routebysender.shtml

Hope that helps!