At my current work, OWA is the external mail source and it doesn't run bad. Adequate for the needs of retreiving bake sale information or for the massage clinic
... Last office resulted in more usage and it was still adequate. I preferred accessing OWA -v- VPN just for email as the VPN overhead (and complexity for dumb users) was too much at times... "Establish your internet connection, Click here, enter password, and you're on" - That was too compicated sometimes
