I want my desktop email on my mobile device also

Add your accounts to your mobile's mail app. You don't need, and in general, can't get Thunderbird on mobiles.

So no one gets Thunderbird on their phones??

Thunderbird is compiled for Windows, OSX and Linux. It doesn't run on iOS or Android. Anyway, it isn't designed for use on a touch screen.

You might be able to run it on a Windows-based phone or tablet, but I think it would be quite painful trying to touch some small controls.

But really, you don't need Thunderbird on your phone. It is just an email client. Whatever accounts you work with in Thunderbird can be handled by the regular mail apps on mobile devices. There is nothing specific to any of your accounts that require you to use Thunderbird. IOW, there is no such thing as a "Thunderbird mail account".