Maintaining DLs is a nightmare in the making. I don't recommend using them
at all, except for small, relatively static ones.
You could, in theory, write Access VBA code using the Outlook object model
to work with the properties and methods of the DistListItem object and do
updates. (Whether you'll be interrupted by security prompts depends on your
Outlook version, which you should always mention when posting to an Outlook
forum.) However, better solutions for mass mailings exist, including Word
mail merge directly from your database.
Sue Mosher, Outlook MVP
Author of Microsoft Outlook 2007 Programming:
Jumpstart for Power Users and Administrators