I've been having an issue since Tuesday where none of my Exchange connected devices can send emails (2 Apple IOS devices, and Outlook). It was all working fine until then. There aren't any error messages. I send the email, it acts like it was sent, and just never shows up in the sent items folder. I've tried this against all of the mail accounts I have setup in Zoho, it doesn't work in any of them (verified against email accounts I have with other providers). 

Anything I send through the Zoho website works just fine. Anyone else seeing these issues?