Email alias missing from drop-down when composing

Question

My email aliases appear in iCloud mail / preferences / accounts, but when I go to select which one to send from one is missing. It's my husband's name but has always worked until recently. My hsuband tends to use his own iCloud address so hadn't noticed it wasn't working. It has disappeared from all devices synced with this account.
All my other aliases appear as a choice but not this one. Any ideas?
Thanks!

Answer 1

I've just solved this.
(It's amazing that Apple's now so big that even support personnel apparently don't know about this fix.)
• Aliases are now fully managed on icloud.com. Go there in your web browser, log in, and go to Mail.
• Go to the Mail prefs (gear icon, lower left), then the Composing tab. There you'll see an item called “Choose which addresses you would like to be able to send from.” (It’s light gray and easy to overlook.) In the rectangle below that, you'll see various email addresses. (I can see 4.) (See attached screenshot.) Turns out that’s actually a scrollable menu of email addresses. But since there’s no visible scroll bar — even when you mouse over the rectangle — there’s no indication that it's scrollable.
• You must click inside the rectangle and drag upward to reveal any hidden addresses below the first few. Depending upon how many addresses and aliases you have, your aliases (if active) should be somewhere in that list. (In my case, the 4, visible addresses were NOT my aliases. But upon scrolling down, there they all were!)
Inexplicably, not only has Apple changed the location of this stuff, they've disabled our aliases without any explanation! That's why the aliases are missing from Mail.app.
• Tick the checkbox in front of any address that you want to appear in Mail.app.
• Click 'Done.'
That's it! If Mail.app is already running, quit and relaunch it — and your aliases should now be available!