Local user for webmail?

I'm a satisfied user of a cPanel-based host. However, I wonder if it would be possible to allow logins to a webmail account using a local username. Eg, instead of having to type "john@doe.net" at the login prompt, just "john" would suffice when there is such an account on the main domain being accessed. Also, it would make sense that the user could select which of the three mail clients to use just once and for all, and then be directed to that page directly instead of having to choose it each time at login. After all, I doubt many users will use more than one client in the end, so this step is unnecessary.

These improvements may only save you 20 seconds each time you log in, but this is something you do thousands of times and it gets a bit annoying in the long run.

 

If you access the domain through IP, it may not work. Simple as that. But if you do access it through a domain name, it could work.