We often get contacted by clients using Google Apps via Outlook asking what does it mean when they receive an email with the subject title of ‘Local Mailbox is Full’.
The good news is, this is a normal healthy message. The reason you’re seeing this is because Outlook has been configured to limit the amount of emails it downloads from Google’s mail servers.
Why? Well Outlook tends to slow down when your mailbox size increases (even at 2GB). In order to give you the best experience we usually limit the local copy to either 1GB, 2GB or 4GB.
When your local mailbox reaches the restricted size, the oldest emails in Outlook are deleted from your local mailbox (don’t worry they are still on the server) to make space for newer emails to be downloaded.