Phone
In the app
Open Support → New Ticket: pick a type (General Question, Suggestion, Issue, Bug, Security Incident, Data Export Request, or Account Deletion Request), write a subject and message, and submit. Your ticket is visible to your organization and to the DMARCS support team, who reply in the same thread.
You can also request an Expert Review or a Takedown Request directly from a flagged lookalike-domain result in Risk Explorer.
Security issue?
See our Responsible Disclosure policy for how to report it safely.