I edited a previous form which users were able to send without regard to their version of adobe (free and pro). I made a miner edit to the form by adding a simple checkbox and now the form can only be sent by users with Adobe Pro. How can I edit the form so it can be sent via email by all users?
You need to use Reader Extensions on the server to be able to do tjat
It's not neccessary to have Reader Extensions if you have Acrobat Pro!
Open your form in Acrobat and then save it as Reader-enabled form.
The location of this menu item depends on your version of Acrobat.
In Acrobat XI it's under File > Save as Other > Reader Extended PDF.