I would write a loop that goes through all the ID numbers you want to send an email to, and creates a string like this:
StrEmail = "email1; email2; email3...."
And then in your message creation use .To = StrEmail
This may not be the most efficient way, but it beats looping through the whole email send for each address...
Please post when you get your solution, email automation is one of my favorite things in Access.
Good Luck,
Alex