Contrary to what I noted earlier http fmos...

Contrary to what I noted earlier, `mod_pagespeed` may be used together with Z-Push (thanks to Grayson Peddie for the hint). Any interference with the relevant parts can be prevented by the following lines in the module configuration:

    ModPagespeedDisallow */z-push*
    ModPagespeedDisallow */Microsoft-Server-ActiveSync*
    

source: Z-Push forum thread