451 Requested action aborted Reject due to policy restrictions

Reason

Significantly more emails signed with your DKIM signing domain were received than expected.

Due to this unusual behavior, the acceptance of further emails has been temporarily rejected.

Solution

If your system is rejected again after completion of the measure, please contact us via the contact form to obtain a higher delivery limit.

Please tell us the DKIM domain you use to sign your e-mails.