@Gleblanc If you wish to have access from outside the organization without using VPN then yes, ActiveSync must be published externally via a solution such as TMG. Microsoft has information in the Exchange docs and on their Exchange Team blog that can point you in the right direction.
If you wish to use UDS externally then this also must be published externally, again via TMG or a similar solution.
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BESX 5.0.4, SQL 2008, Exchange 2010 SP2 RU4a