If you can‘t send an email with iOS 11 and an Outlook.com or Exchange mail account

You might not be able to send email with an .com, , or account until you to .

If your email account is hosted by on Outlook.com or 365, or an on , you might see this error message when you try to send an email with iOS 11: 20;Cannot Send Mail. The message was rejected by the .21;

To fix the , update to iOS 11.0.1 or later.