Agree the technical aspect isn’t that complicated if you are dealing with users who know what they are doing.
The technical aspect isn't complicated on the back-end at all. The real trick is going to be building a really simple solution that any iCloud user can take advantage of. This is why I originally wondered if Apple might go so far as to get into the DNS hosting game, but that's extremely unlikely for all the reasons that others have pointed out. I definitely can't see Apple relying on users to figure out how to set this up for themselves. In fact, part of me suspects Apple won't even give more tech-savvy users the
option.
That's actually why the possibility also suddenly occurred to me in the post above that Apple might not allow for just any domain to be used. It could simply issue "custom email domains" under a TLD or other domain that it already owns. That would be the most turnkey solution by far, and it wouldn't be a big deal for Apple to provide basic DNS services in that case either, since users wouldn't be using those domains for anything else.
If that turned out to be the case, it would obviously be a huge disappointment for many, but knowing how Apple rolls with iCloud Mail, it honestly wouldn't surprise me. As with most of its iPhone apps, Apple is happy to provide just the basics and leave power users to find better solutions elsewhere.
But still it needs to be tested before being called a live feature I think. Firstly to make sure the UI to set this up is working as intended and confusing users.
You're right that there's a bit of an adoption curve there, but I still think Apple is more likely to slap a "beta" label on the whole thing, like it did with iCloud Photo Library when it first launched. Again, though, that's all UI stuff, and Apple doesn't seem to be overly concerned with what users think of a UI before launching it. Just look at how controversial the changes are in Safari for iOS 15 and macOS 12. The iCloud Mail UI is in the process of being redesigned — you can see it at beta.icloud.com — but it's also clearly still a work in progress.
And secondly (more importantly) to catch as many technical glitch or edge cases as possible which might cause emails to be lost (it really would look bad to have headlines saying the iCloud is dropping emails fro some users).
That would really only require back-end testing, not a public beta. The core email technology we use today has been around for over 40 years, and Apple has even been directly involved in some of the IETF working groups for various internet technologies. If Apple can't figure out how to receive and properly route emails for additional domains, it has no business running a mail server in the first place 😏
iCloud Private Relay and Hide My Email are both more complicated than custom domains, and yet Apple already has those up and running in the iOS 15 betas. That said, the fact that custom email domains are nowhere to be seen yet definitely implies that either it's not launching with iOS 15, or it's not going to be anything like what many of us are expecting.
Then there is what
@TriBruin mentioned about less technical customers (if they are left on the sideline it is fine, but if there are some kind of technical integration with a DNS hosting partner and auto-setup, this probably needs to be tested as well).
I don't think Apple will leave anybody on the sidelines, as that's not really Apple's style when it comes to iCloud. In fact, that's arguably the reason iCloud Mail (and related services) have seemed so dumbed-down over the years. Apple prioritizes "simple and accessible" over "powerful and feature-rich."
Again, though, other than the UI, all of the technologies involved in doing this are foundational internet standards and have been well-established for years. I was running multiple domain names on email servers back in 1998, back when one had to submit DNS registrations via email templates. There's no magic to any of this on the back-end, and Apple isn't developing anything new in that regard. Even working with DNS hosting partners has already been done many times. For example, Google Workspace (nee G Suite) has offered a one-button configuration solution for over a dozen major DNS providers for almost a decade now.
The only possible new ground Apple would be breaking here is providing an even more seamless user experience in setting this up. That would be a big deal, and very much an Apple thing to do. That will need to be extensively tested — no IT project manager in their right mind wouldn't put that through testing — but it may not be user-facing testing.
iCloud Private Relay and Hide My Email are more relevant because those UIs are in the actual iOS 15 betas. We don't know if Apple plans for let users configure and manage a custom domain in iOS or macOS directly, beyond the code that already exists for setting up and choosing aliases in the iCloud Mail settings.
It really comes down to exactly what this feature will be, but I think it is looking less and less likely they we will get a full-fledge custom domain service launching in production alongside iOS 15.
Personally, my gut feeling has been that we won't get a "full-fledge custom domain service" launching at all.
Remember that the only thing we know about this right now is
one sentence from Apple's iOS 15 Features page:
Personalize your iCloud Mail address with a custom domain name, and invite family members to use the same domain with their iCloud Mail accounts.
This thread (and others like it) are rife with speculation — much of it
educated speculation, to be fair, since most of us know how these things work with other providers. We've all been hoping that this will be something akin to what Google Workspace or Fastmail offer, but I after taking a step back and thinking about it, I really suspect it's going to be much less.
Either way, it's important to remember that Apple has nothing about it, and the sentence above doesn't even say "your own domain name" but rather simply "a custom domain name." It's also worth noting the singular use of the word "domain" here.
For all we know, Apple might be planning nothing more than allowing users set up
subdomains of iCloud.com for their families (e.g. "
john@doe.icloud.com" and "
jane@doe.icloud.com"), or even another second-level domain they still control, like me.com.
In fact, the more I think about this, the more I think we're all setting ourselves up for disappointment.
Even though it would make their wording a bit missleading, one possibility still is that all they mean to say is that they will allow us to setup aliases for our custom domain address on the iCloud website. In that case agree that there isn’t much testing required (that feature existed years ago and was removed).
That honestly wouldn't entirely surprise me, but I do think this will be a little bit more than that. I suspect one of the reasons Apple removed that feature years ago was because it really didn't work all that well for the average user, who still needed to have another email account or forwarding service to handle incoming mail. It also created new problems as email validation technologies like SPF and DKIM entered into the mix — this is where there was a real potential for messages to get lost in the sense that they'd be rejected or flagged as spam by the receiving servers.
If Apple goes back to that, it will actually be worse than if they simply left users to figure out how to set up MX records for themselves.
