Sounds more like you should be looking for a SaaS solution that’ll do all the above and more. They are always on,
no ‘activating’ when needed plus they include multi-layer filtering and reporting as well.
Look at our service, Cleartext ClearEmail and others like MessageLabs and MX Logic. Most of our clients are
ex-Symantec, McAfee etc.
If you’re keen on MessageOne without looking at anything else then you should be fine as they also have a good
reputation in the market.