Running Outlook 2010. Somehow about 1/3 of my Contacts have their Internet Format set to: "Send using Outlook Rich Text Format". My guess is that these are the ones that I imported from other applications over the years. I have thousands of Contacts, and many of the Contacts have multiple email addresses, so it would take forever to edit all of them by hand. How can I change the Internet Format of all of my Contacts' email addresses to be "Let Outlook decide the best sending format" - en masse?
Thanks in advance for your help!