rspamd: allow mismatch hdrfrom/username
I propose we set allow_hdrfrom_mismatch = true;
and allow_username_mismatch = true;' in
/etc/rspamd/local.d/dkim_signing.conf` if reject_sender_login_mismatch is in use.
https://www.howtoforge.com/community/threads/rspamd-not-signing-email-alias-with-dkim.86690/