Email times out and won't load

This issue only happens on our deskop device.  Comcast takes forever to load but it does load.  I sign in and click the little envelope.  The email loading page times out and will not load.  We have tried all of the trouble shooting hints but nothng helps.  This only happens on this device and only with comcast site.  Other internet sites work fine.  We use google. It has been going on for months.  Very strange.