Q: Apple Mail trying to send from old email address

Thanks Dominic.

Okay, I followed that advice, but the only email address available in that box 'Send new messages from' is his OLD email address. The only other option is 'Account of selected mailbox'. (i.e. His actual iCloud email address doesn't show up in the drop-down list at all.)

I left it as 'Account of selected mailbox', and tried to send a test message, but it still threw up the same error message and it still showed as 'Sending from joebloggs@oldemailaddress'...

So I am still none the wiser here. Getting desperate now...

Hi again.

Well, not specifically, no. In fact, it was just 'Inbox' that was highlighted in the sidebar when I sent the test message.

But as I have deleted all other accounts that he had in Mail, apart from his iCloud one, should it not default to his iCloud mailbox?

Some further points. I don't know whether they're relevant or not.

1. I'm sure it should make absolutely no difference at all to his iCloud mail account in theory, but his Apple ID is his old email address.
2. He can receive messages on his Mac through his iCloud account; it is just the sending of them that there is a problem with.
3. He can receive and send messages through his iCloud account if he uses his iPhone, so the account is sound and it looks like it's a local issue in his Mac.
4. I noticed, before I deleted his old account from Apple Mail on his Mac, (so that he still had two accounts active), that something seemed odd when bringing up his new message window. If I have more than one mail account active in Mail on my Mac and I bring up the new message window, Mail adds an extra line above the message body entitled 'From', an in that line I can choose which address to send from. But in my neighbour's new message box it never added that extra line, even when he had two active email accounts.

Yes, thanks again.

I've done all that, but he still has the problem.

(His 'Send new messages from' box looks exactly like your screenshot, but there is always the option of his old address as a drop-down underneath it, even though there should be no vestige of it remaining after deletion. I never select the old address, but I'm curious as to why it should still be thrown up in the drop-down.)

Thanks Glenn, I followed your advice and he now has a working Apple Mail app again.

I was a bit confused with stage 2 (Mail settings at iCloud.com) because there was no address list at all in the Composing tab there, but i signed him out of iCloud via system prefs, signed him back in and he was up and running.

I've tried several times to mark your answer as a solution, but the link seems dead for some reason. [edit: Yes it did work, but it didn't seem to when I did it...]

Ahh. I see that in your screenshot now. But in my neighbours settings there wasn't a 'Send From' section in the tab.

Nor is there in my own.

I'm not sure how old they are, but they were created after the MobileMe thing that preceded iCloud.

But... You got me thinking. I followed the instructions on how to create an alias, created one, and now that tab on my iCloud.com Mail Prefs DOES have that 'Send From' section to it.

Splendid! Two new things I've learned today.