This error his hard to troubleshoot because it can be several things, but basically it is telling you that it is taking an unusually long time to recieve exchange data. The error is very common, but if it becomes an issue here’s a small list of what to check and/or improve:
1. GC and Exchange server performance issues.
2. WAN network performance and network performance in general.
3. Reduce large mailbox sizes
This is not a complete list, but it is a start.