We run Exchange 2010 with Outlook 2010 clients. Recently we had a weird problem where Outlook was showing the mailbox was approaching it’s 200MB limit, even though the mailbox size limits in Exchange had been increased to more than this (500mb Warn , 600Mb Send and 700MB Prohibit Send and Receive). We tried increasing the values and enabling and disabling the default Limits. In the end the only way we found to fix it, was to move the Mailbox to another mail database. This solved the issue. #Random