my apologies, i mean it's custom addresses (xxx@yourdomain.com), not custom domain
my apologies, i mean it's custom addresses (xxx@yourdomain.com), not custom domain
.setReject('Unknown address') and that actually seems to properly be detected by services such as GMail (see image). Is there some kind of list of "official" rejection messages that get mail services properly react to or do they just guess based on the rejection string?
I should actually test this)

concat("https://www.example.com", http.request.uri.path), and keeping query string, and probably 302 and not 301 so you can change it without being cached forever

x-robots-tag noindex instead of a robots.txt
(550): 5.4.6 Email was forwarded too many times. one, I would look in to the final destination that you're trying to forward your message(s) to.(521): 5.3.0 Upstream error, please check on the Activity Log (https://dash.cloudflare.com/?to=/:account/:zone/email/routing/overview), and not only in a bounce message, it could also sound like you have a loop, where it's bouncing between different Cloudflare Email Routing domain.a@cfer1.example.com -> b@cfer2.example.com -> c@cfer3.example.com -> d@cfer4.example.com -> example@example.netd@cfer4, to find the actual rejection message, that the mail server for example@example.net rejected you with.(521): 5.3.0 Upstream error, please check in a such scenario.


