Have form (created in Adobe DC Ver 2015.006.30527) with a mailto: button. For users with Outlook it works fine, but for users with Thunderbird we get an Adobe error that says "One of the specified recipients is not resolvable" PC has Adobe Reader version 2021.005.20058. On the Thunderbird PC I can type Mailto: into the url for chrome and thundeerbird opens with no issue. Mailto:firstname.lastname@example.org works as a url also in Chrome. so it does not appear to be a ThunderBird issue as it is the defaul email. How do I get MailTo: button to work with Adobe Reader and ThnuderBird?