iOS Boxer 4.9
All ActiveSync clients including iOS Boxer may sync intermittently or pause for mailboxes with very high volume or full calendars due to a server side issue in Exchange. In order to determine if a user is encountering this issue, navigate in the Boxer logs (Boxer > Settings > Support > Send Logs) and look for the following error:
"[TBAS] SYNC LOOP DETECTED for folder"
This error indicates Exchange has provided an incorrect response back to iOS Boxer, and iOS Boxer is attempting a workaround.
We have informed Microsoft of the issue and this article will be updated once a resolution has been determined.