Hello! I’ve configured Cloudflare to forward all emails to my gmail account. After sending some tests mails, I can see those mails are forwarded in the dashboard.
There are several email providers doing some fancy things, but failing to (properly) inform their users of such.
Gmail is for example known to attempt to avoid duplicates in your messages, which means if you are sending a message from the exact same address that the email routing will also pass it over to, Gmail will silently discard the message.
The solution would be to try from another address, and preferably also from another provider (to also rule out that e.g. external locations is actually able reach you too), when testing whether things work or not.