no outgoing mai

I suspect Apple is forcing everyone to app-specific passwords, and thus 2-factor authentication. I'm having the same problem, "called" Apple support, and their proposed "solution" was that I delete my iCloud account and recreate it. When I indicated that I didn't want to do that (because it's a pain to re-sync everything and I'm in the middle of working) they hung up on me.

(I don't know why Apple's solution for every iCloud problem is to make you delete your account and recreate it. It's becoming like dealing with Windows support. Next they'll be asking us to do a clean install of macOS to fix the smallest problem. But, it can be a real pain to delete your account and recreate it, especially if you choose not to delete your data, and then it doubles up your calendars etc when you recreate.)

Looking at the Mail server settings for iCloud email clients - Apple Support it says:

SMTP information for the outgoing mail server

• Server name: smtp.mail.me.com
• SSL Required: Yes
  If you see an error message when using SSL, try using TLS or STARTTLS instead.
• Port: 587
• SMTP Authentication Required: Yes
• Username: Your full iCloud email address (for example, emilyparker@icloud.com, not emilyparker)
• Password: Use the app-specific password that you generated when you set up the incoming mail server.

If you click on the "app-specific password" link, it indicates that, "To generate and use app-specific passwords, your Apple ID must be protected with two-factor authentication," whether you want to use 2-factor authentication or not.

So, they appear to have silently (without informing anyone) made a change which effective disables SMTP for previously setup accounts. Either that, or they just broke it on their side but haven't or don't intend to revert it to the previous behavior.

I had this very same problem start happening last night. After troubleshooting everything I can think of, I found the specific problem by accident. I have been using my @me.com email address for all new and reply emails. The same account can be used by interchangeably sending from @mac.com or @icloud.com instead of @me.com. The @me.com address stopped working but sending from the other two works. Now I'd just like to know why. I couldn't find anything online about it.

Morgan

IOS 12.0.1

OS 10.14

It's not actually deleting my iCloud account that they wanted me to do, but remove the account setup from my Mac. You shouldn't need to back up any of your iCloud email, notes, etc. because it is "backed up" in iCloud, but the stuff it asks you if you want to keep or delete (Calendars, for sure, and I forget what else) when you remove the iCloud account setup, you need to delete. Otherwise, when you redo the setup of the iCloud account on your Mac it will duplicate all that stuff. If you do delete it, it will sync it back down when you set the iCloud account up fresh.

I've never had to do that on iOS devices, so I'm not exactly sure how it works there.

But, again, it's ridiculous that the "preferred" method (or at least the only method Apple offers) for fixing any and all iCloud problems is to delete and recreate the account setup on your device. It's a time consuming and disruptive process, and, since they give no reason why it should be necessary, you don't really know if it will fix the problem or for how long.

It's equally ridiculous that Apple support hangs up on you when you say you don't want to delete your iCloud account setup. If they have no idea what's wrong, they shouldn't force you into disruptive processes that may or may not fix the problem. If they do know what's wrong, they should explain what is actually wrong and why.

According to information at https://macsources.com/icloud-based-mail-currently-experiencing-issues-news/ this is an outage unreported on the Apple system status page, with no ETA for a fix, so save yourself the trouble of trying anything drastic for now.

I had the same problem yesterday and last night but this morning everything seems to be fixed from Apple's end. Hopefully for you too?

In the process, I also found that sending mail from a web browser, logged into https://www.icloud.com/#mail worked fine while using the OS and IOS mail apps did not.

That's why I objected to being asked to do it. No explanation of why it's necessary or what it would fix, just seems like they want to start with a Hail Mary and hope the problem goes away.