What SPF, DKIM and DMARC do for email

Apply this guide to your situation

This answer covers “What SPF, DKIM and DMARC do for email”. Read it with the summary and confirm that the symptom and service match what you are experiencing. Available options can vary by plan and account setup.

• Before changing anything, note what you expected, what happened and roughly when. Check whether the issue affects one page or the whole service.
• Save the full error message and note recent changes. Hide passwords, access codes, personal data and keys before sharing screenshots or logs.
• If a step requires administrator access, restarting services or editing server files, stop if you do not administer that server. Send support the service name, error and checks you have already made.