DANE & DNSSEC for mail
@Manoj form the community told me to create here an issue for that: https://community.e.foundation/t/higher-ciper-dane-for-mail-please/8356
I have tested the mail service against My Email Communications Security Assessment (MECSA) from the EU. The result you can find here: https://mecsa.jrc.ec.europa.eu/en/finderRequest/42625b68ac2493b3ae7aefaadb0dbfaf
There you can see, you don't use DANE or DNSSEC. So my request, use DANE and DNSSEC, please. That will helpt to secure more your service, and it is really easy to setup.