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.
- I cannot connect to the internet using a mobile data connection on my Lumia phone
- I cannot send or receive multimedia messages on my Lumia phone
- How do I disable or reset the text suggestions on my Lumia phone?
- The block number feature disappeared from the call history on my Lumia, how do I get it back?
- How do I configure my number to be private when I call someone on my Lumia phone?