Migrating email hosting from Cloudflare to iCloud Mail

Up until now, I’ve been using Cloudflare Email Routing to forward all emails sent to the hello@abstractnonsense.xyz email address to my personal iCloud email. This is seamless to configure, as Cloudflare is my domain registrar and keeper of my DNS fiefdom. However, this service is a one-way pipe: if I want to respond to emails, I have to do so from my personal email. I’ve now migrated to Apple Mail’s Custom Email Domain support, which is bi-directional. This fits in nicely alongside iCloud Hi...