Submit Form giving error "An error occurred while sending email..."

Hello,

I have a submit button programmed to Submit Form to mailto:email@example.com. It works on every other computer using the same operating system, same update, and same setup. Here it the full error:

"An error occured while sending mail. If you are not sure how to process further, you can save your form and return it manually using your Internet email service."

I have un-installed and re-installed the entire Office suite, Adobe Reader DC (including using a cleanup tool from Adobe Labs), have done a screen to screen comparison of Adobe Reader DC and Outlook/Exchange settings on a working machine.

Normal behavior is the user clicks on the button and it launches a draft e-mail in Outlook with an attachment of the PDF and to the e-mail address programmed. No matter what I change, all I get is that same error. This has been going on since March 2019 and i've yet to find a solution.