Unable to use custom domain Email on new Mac?

[MarkVeldhuis]

I noticed that on any new Mac install, I am not able to use the Email-addresses for custom domains I set up through iCloud+.
When I click "From" in a new message in Apple Mail, the addresses don't show up. Three custom domains with a couple of addresses each, and apparently I am not able to send messages from them.
I first noticed this when I set up the beta of Sonoma on a separate partition on my M1 Air. Thought it just was a beta-bug. But now I've got a new 15" MBA, with Ventura (updated to the latest version). Same problem...
Any tips in how to get this to work again?

 

[JonaM]

I've had the same problem and have been having to rely on 'reply-to' as a workaround. I jumped straight to Ventura so I assumed this was just an annoying restriction in Mail

 

[MarkVeldhuis]

I've had the same problem and have been having to rely on 'reply-to' as a workaround. I jumped straight to Ventura so I assumed this was just an annoying restriction in Mail

It works on Macs I used when I set up my custom domains. But any new install, including a new MacBook Air, has this problem.