Hi There,
Every time I switch on the “Proxy” function for my domain in Cloudflare, email transport stops.
I;ve searched and found a couple of posts similar where people are using “mail.their-domain.com” as MX records, but for me have the MX records of my actual email server provider.
Proxying the www record (etc.) should have no impact on your mail delivery. Are you using a web portal like webmail.example.com? If so, you may not be able to proxy that, and will need to talk to whoever is hosting that for you.
Do you receive any errors when attempting to send/receive mail? Which record specifically is causing the issues?