On the tmo website it also says this:
If you have t-zones service you can access your personal mailbox from
your t-zones enabled phone. From the t-zones main menu, navigate to My
E-mail to access your mailboxes.

So if you have the 5.99 tzones plan and set up tmobile to check your
email (as described in a previous post) you can get regular email on
your phone that way too.