Mail Tester is a tool to test your e-mails for spam filters.
It gives accurate indications why your e-mail could be tagged as spam.
You’ll get a score on several topics, with clear descriptions how to solve the spam indications.

Just open the website https://www.mail-tester.com/ and sent your e-mail to the given e-mail address.
Click the button ‘test your score’ and see the results!

After finetuning your e-mail, you can test again untill you reach a good score!