I'm looking for a solution to enterprise storage of project-related email. We're an Office 365 shop currently using public folders for storage of project email. They're convenient as they can be exported to PST when a project is complete, however they're inconvenient (and slow when attachments are present) for my users to drag/drop messages into whenever they receive or send. Looking for input on a solution that may be a bit more automated for email filing. Any ideas?