how to add a field to the email subject?   If I put this in the subject line of email '{mls4} MLS Change Request {fullName1}' will it convert pro

Can you tell me how to add a field to the email subject?  

If I put this in the subject line of email '{mls4} MLS Change Request {fullName1}'

will it convert properly? 

Yes, the variable listed under the content of Autoresponder email should convert properly.

You can also select the "Form Fields" from the Editor's tool bar and select the variables listed in the popout menu, and copy the same from the editor, if you don't find the variable already listed.

Hope this helps.