I am working on a Application with firebase. I want to validat a users email, but since Firebase doesn\'t allow to change the verification message (To help prevent spam, the
Nowadays the best procedure (with just 1 step) was for us to develop an HTML file with the exact content for each of your templates (Email-Verification and Email-Change, including even the snippets %...% in the right place) and send them as attachment in the Troubleshoot form as mentioned by Alfonso in the comments of this question.
If you send the exact email HTML template file, you leave Google's people with no questions for spamming purposes other than quickly validating your HTML content and approve.