DKIM Fails DMARC Alignment when sending on behalf of account with a different domain
Could you change your DKIM implementation to use the RFC5322From domain in the DKIM signature 'd=domain' as
when you have multiple domains within a tenancy, DKIM Fails DMARC Alignment when sending on behalf of an account with a different domain to yours e.g. user1@domain1 sends on behalf of user 2@domain2.
This is because Microsoft DKIM implementation uses the RFC5321MailFrom value in their signature for the 'd=domain' but DMARC checks DKIM alignment by matching 'd=domain' to the domain in the RFC5322From. https://tools.ietf.org/html/rfc7489
Jeremy Bradshaw commented
I'm all out of votes, but I would vote otherwise.