1 Oct
2022
1 Oct
'22
2:45 p.m.
Oct 1 13:31:46 xxxx sendmail[30321]: 291BVjjx030318: to=xxxx@gmail.com, delay=00:00:01, xdelay=00:00:01, mailer=esmtp, pri=122536, relay=gmail-smtp-in.l.google.com. [142.250.102.27], dsn=2.0.0, stat=Sent (OK 1664623906 gs19-20020a1709072d1300b00777a40d515dsi4096082ejc.456 - gsmtp)
I just tested for you, enabled the sieve forward, send test mail and the forward is being accepted by google.
It looks to me you're dismissing the fact that it only concerns the forwarding of mails that have originally a "bogus" Message-ID.
That's the only way to trigger the issue. Other mails (that are missing Message-ID or having RFC compliant Message-ID are forwarded and accepted just fine by gmail :)