Zoho usernames for my domain?

I am testing Zoho right now in the hopes of using it as an alternative to GMail for my own domains. If it does everything I want, there is a lot of potential of bringing in several domains with lots of users. However, one of the annoyances I found is that when I setup a new email account for my domain, the user still has to create a Zoho username. For example, if I create myname@mydomain.com and send that information to the user to login, when they login for the first time, they are required to create a new username that is unique to Zoho. Once they do that, will they get emails that could be sent to that name @zoho.com? That may be a deal breaker for many of my customers.

The way Google does it is if my email address is myname@mydomain.com, that is also my login, and I don't have to create a gmail username to go along with it.

Is there any way to get around this limitation? If not, is there any future plans to do away with this?