Was curious if anyone had some thoughts if this is possible (I think it should be, but not sure where to start or how to go about it.)

I would like to create a site that allows people to create an email address, but give them the option to select from several different domains. Any thoughts on how this could be done?

They would go to www.home.com
And then create an email as;
JohnDoe@example1.com or JohnDoe@example2.com, etc.

Any thoughts on how to go about this.