I have about 21000 contacts in a folder in Outlook, and will mail (physical
mail, not e-mail) about 100 of them each week. I know how to select the
contacts in Outlook and do the actual merge, but can't find any way to keep
track of which contacts have and have not received a given mailing, so that
I don't include them the following week.

I was intending to use the journal first, but that would be a manual process
per contact which is too much for 100 contacts, and would still leave me to
read the journal each time.

I then thought of using flags, so red would be for week one, green for week
two etc in whatever cycle I want, and then view by flag, but although I can
use the coloured flags contact by contact, there appears to be no way to
apply a given coloured flag to a whole group of contacts at once. I can only
add flags to a toolbar in e-mail folders, not in contact folders.

So any ideas? How do people keep track of which contacts have and have not
received a mailing, and when?

Thanks,

Mark