I looked into it and it looks like the FROM address was failing validation. It didn't like the email from name you were using:
"Moorish Amexem Universal Region Indigenous / Aboriginal National Services"
The slash was encoded and needed to be decoded in order to display properly, so I updated line to:
"fromAddressDisplay" => "".html_entity_decode($_SESSION['longname_business']) ."",
That seems to have fixed it.