The GMail original mail message states: DKIM : 'FAIL' with the domain mydomain.com
The AcyMailing Spam Test states:
0.1 DKIM_VALID Message has at least one valid DKIM or DK signature
0.1 DKIM_VALID_AU Message has a valid DKIM or DK signature from author`s domain
0.1 DKIM_VALID_EF Message has a valid DKIM or DK signature from envelope-from domain
DKIM is also well recognized by https://www.mail-tester.com/spf-dkim-check
Hence, why do I get a 'FAIL' from GMail?
Despite the header:
Authentication-Results:
in45.mail.ovh.net; dkim=pass (1024-bit key; unprotected) header.d=mydomain.com header.i=@mydomain.com header.b="dpZjdFpL"; dkim-atps=neutral`