Can m0.guardmail.cf receive emails?
Yes, m0.guardmail.cf can receive emails.
Should you allow users to sign up to your website using the domain m0.guardmail.cf?
No, m0.guardmail.cf is a throwaway domain and
should be blocked.
How to block the disposable domain
You can use MailCheck's
free API to automatically block throwaway emails.
Read our documentation to get started. No registration required.