Checking if SPF, DKIM, and DMARC are set correctly

Question

I have a mock domain name: dev.chacchan.ml I've configured SPF and DKIM to ensure nobody can use my SMTP credential to send mail outside SES This is my DNS config:

How can I send mail from outside SES to validate my configures are working correctly with an expected result is e-mail being blocked

Answer 1

Whether an email is delivered depends on many factors, in particular the configuration of the receiving mail server and the reputation of the sender. It is thus really difficult to isolate individual factors with tests.

Make sure you also have a valid DMARC record with a reject policy. Afterwards, you can test your configuration with a tool such as mail-tester.com . Alternatively, you can interpret the Authentication-Results header field, which your personal mailbox provider likely adds to incoming emails, yourself.

There are no guarantees that not-authenticated emails are blocked by receiving mail servers. Configuring SPF, DKIM, and DMARC properly is the best you can do as a sender.