Client has 3640 at their mail co-lo. They have a pix515 at the office. I now know that you can't terminate their clients to the pix and let them hop into the L2L to get down to their mail. I am hearing that I can do the reverse. Terminate the clients on the 3640, setup a L2L between the 3640 and the pix, let clients ride the L2L after connecting to the 3640. Is this right?

I have looked high and low on Cisco, so if anyone says yes, could you point me to the right place or show me a config!

thanks