Apple says it is working closely with Microsoft to fix an issue that prevents Outlook.com, Office 365, and Exchange 2016 account holders from sending or replying to emails using Apple’s native Mail app in iOS 11.
Apple published a support document on Tuesday, September 19 – the official launch date of iOS 11 – to acknowledge the issue affecting users of Microsoft email servers.
If you can‘t send an email with iOS 11 and an Outlook.com or Exchange mail account
You might see an error message that says „Cannot Send Mail. The message was rejected by the server.“
If your email account is hosted by Microsoft on Outlook.com or [...]