Google provide a free service for hosting up to
50 email accounts 10 email accounts (lowered May 10, 2011) for your custom domain. Once setup the users can log into Gmail with email@example.com and as you know Gmail works great on any android/iOS device.
Not many people seem to be aware of this service, so I thought I’d put it out there.
Google Apps is fairly straight forward to setup, firstly you need to verify you are the owner of the domain.
Once that’s verified it’s as simple as pointing your MX records to google and setting up your users.