I've recently had the opposite problem. I had an external host receive email for a domain and then forward to gmail. The message envelope is changed, and SRS

I've recently had the opposite problem. I had an external host receive email for a domain and then forward to gmail. The message envelope is changed, and SRS records are updated to be from the forwarding domain and DKIM is valid. However, over the last 2-weeks or so, Gmail has been hard rejecting the majority of the mail at SMTP time, which has caused a big pain! I really wish I could say "trust all mail from this mail server, but please also do Spam checking".