There are also several third-party tools that streamline or automate this functionality beyond what ExMerge provides. Assuming you're logged in using an account with full access to the mailboxes you want to export, ExMerge allows you to extract messages based on a variety of criteria.
This extraction can include all messages, messages within specific folders, messages with specific date ranges or messages with specific subject string matches or attachment names. Messages are exported to one or more .pst files. The .pst files can be opened using the Microsoft Outlook 2007 client. You don't actually have to import the .pst, you only need to attach it using the Open Data File menu option.
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