iCloud+ custom email domains should be bettersource • domlaut.com
Another worrying thing about how Apple implemented custom domains for iCloud Mail is some amount of domain address and Apple ID coupling. I hold that these two should be entirely separate. If you control a domain, you’re already able to do whatever you want wrt. where any emails for that domain end up, making any arguments about security a moot point.
I have many of the same issues with iCloud as Dominic, and the biggest one for me is this ownership of an email address that has in any way been associated with an Apple ID. I was using an email address with this domain with one Apple ID and when migrating the custom domain in iCloud to a different Apple ID I was unable to recreate this existing email address. Apple support was no help and I finally bit the bullet, and decided to migrate my use of that address to a new one that I could add and use successfully.
In order to migrate my use of the old email address away from some services and various ties I temporarily switched to using Hover to host my email instead. When I did this I also found that Apple would neither successfully send to, or receive from, any email for the old address from my @icloud.com address. I tested this issue with multiple other people using their @icloud.com accounts and had the same results. Gmail, etc. had zero issues. So once a custom domain email address has been hosted with Apple it seems like it is forever locked behind their MX as far as their servers are concerned. Not a great attribute, to say the least.