To fix the problem, you need to limit the mailbox size in GSSMO. Or, you can increase the size limit of your PST file in Outlook.Consult your Microsoft documentation on how to do this.
Then I went to Microsoft’s own “What’s new in Outlook 2013 Preview” page, where I discovered the same comment about new OST files being 40% smaller.
But then I read all about “By default, if Cached Exchange Mode is enabled, Outlook 2013 Preview will only cache email messages from the last 12 months and remove anything older than 12 months from the local cache.
Users can view messages that were removed from the local cache by scrolling to the end of an email list in a folder and clicking the message Click here to view more on Microsoft Exchange (see below).
Users can also change how many email messages are kept offline.
has long been a good source of information about Outlook.
Its piece on “All you need to know about Outlook 2013 Preview” said that Outlook 2013 uses a new compressed format for the OST which results in files up to 40% smaller than before.
You, as the IT Administrator, can change the default age or enforce the age of email messages that are removed from the local cache by using Group Policy or the Office Customization Tool.” Eureka!
Although I have no doubt that Microsoft has made many wonderful tweaks to the Outlook 2013 OST file format, I suspect that the reduction in size that I’ve seen is heavily influenced by the change in caching behavior.
Outlook 2013 clearly doesn’t think that this information is important, hence its eagerness not to cache the item.