Do not send messages from Blogger blog

There is a problem with messages not being sent from the Blogger blog on the site to email, knowing that this problem only exists when installing with Cloudflare.

Hello, do you have any relevant error messages to share when trying to send the emails?

Any DNS record used to send email traffic must be grey-clouded(DNS-Only) to bypass the Cloudflare network.
See: Identifying subdomains compatible with Cloudflare’s proxy