The mailbox may have some emails with an excessively long subject line that are not supported by Windows Phone 8. Once you have removed the suspect mail item (i.e. cleaned the mailbox or move the suspect mail to a folder that phone does not sync) the error will cease.
- NFC pairing of the Wireless Charging Plate (DT-903) is not working Device Hub, what can I do?
- Which Microsoft and Nokia branded accessories have special support in Device Hub?
- Can I zoom the images with PhotoBeamer app?
- What should I check if push notifications for XYZ third party apps not coming or coming late after Lumia Cyan update?
- How do I enable receiving of files automatically using Messaging+ application on my Lumia?