We just migrated to zimbra, but several outlook users have received messages like this while using the outlook connector.
Local Failures were detected. No action is required.
This e-mail was generated for technical support purposes.

Sync Type: Initial Sync

Sync Token (before request): no sync token

Sync Token (most current): 9651

Store: Zimbra - <user's name>

Computer Name: <computer name>

Version: 5.0.2817.11

Error IDs:
id (6741) type(message) message(failed to synchronize this item)
Everything seems to work, and the messages don't seem to repeat. What does this mean exactly? Is the connector unable to read certain messages? How can I determine which message and why? Would the message still be available in the web interface?

Apparently you can prevent messages by adding a registry key, but I would assume the message indicates an issue I should be aware of, but doesn't explain it very well.