If you use Simplelogin with your iCloud email, how has your mileage been?
I just tried changing my email on studentaid.gov to a simplelogin alias (using SL is a habit at this point) and I got notifications that emails from it were bounced while trying to verify the email change with sent codes. I looked it up and found a bunch of Reddit posts about issues with SL and iCloud.
I use it in tandem with proton, so the quantity of emails going to iCloud are less, however I’ve not experienced this kind off issue with either.
Generally if a service is going to have issues with SL, it’s at the point when you provide the email that it says it’s invalid (likely due to the domain being on a black list to prevent use of the service)
No I did end up changing my studentaid email to an SL alias, though I might wanna change it back if it keeps having issues. The issue is that icloud bounced the email, and SimpleLogin itself gave me an email each time one got bounced, with to go to simplelogin.com and see the bounced email. This is the title for each one
An email sent to your alias redacted@simplelogin.com from donotreply@studentaid.gov was bounced by your mailbox redacted@icloud.com
Depending how deep you are into using the service, this might be an indicator to start shopping around for other options, as there are some that provide multiple domains and unlimited aliases for the cool price of $0 versus whatever Proton charges you...
...Especially if iCloud makes the other side of the equation difficult.