iCloud Cannot send mail from an iPhone but is ok on Mac and iPad

[LeeW]

Has anyone seen this before (image below). My wife's iPhone 14 Pro is giving this message, we are set up exactly the same and I have checked all settings as suggested and can find nothing out of place. It just started happening without any apparent reason.

If she sends mail from her Mac or iPad or even through icloud.com it sends just fine. So isolated to the Phone. Just can't figure out where it's going wrong.

Scratching my head on it for the last day or so. I use a custom domain for the last 6 months or so, this is the first mail-related issue. Everything is fine for me on all devices.

 

[circatee]

And a soft reset of the phone, along with removing the email account and adding it back didn't help?

 

[LeeW]

And a soft reset of the phone, along with removing the email account and adding it back didn't help?

Tried that, no difference.

 

[circatee]

Me again, technical brain is tinkering over here.

As a test, add another email account, possibly one that has never been on the device before, then test it.
This might confirm the issue is not account related on the device, but a software issue. Might even need to reload the iOS...

 

[LeeW]

I had to completely remove the domain from iCloud and add it again along with redoing the DNS. That fixed it but a bit extreme.