Just wanted to let the community know that there appears to be a bug with the Active Sync protocol in the latest Android 4.4 released on the Nexus 5. It is being reported here:

https://productforums.google.com/d/m...k/4GpCX-KHrA4J

https://code.google.com/p/android/is...sort=&id=61785

I am experiencing the same problem. The symptoms are roughly:

1. Setup a "corporate" account using the native client
2. Enter all relevant details which are confirmed
3. First batch of e-mails, contacts and calendar come down fine
4. The device will no longer receive new e-mail messages
5. Upon further inspection the device is stuck in a continual sync loop
6. This not only stops it from receiving e-mails but also drains the battery

Hope this helps someone from banging their head against the wall!