Merge to email button gone

[Frankie Deschacht]

After a re-installing Office XP I noticed that the "Merge to email" button
is greyed out.
For the sake of clarity, I did not install Outlook with Office, I have
Outlook Express v6 as my main client (with all the latest patches and IE6 SP
installed), so I don't think that is the reason, or is it? (In my previous
setup, I didn't have Outlook either).
Any ideas how I can make that button function again?
BTW. Is OE6 MAPI compatible, as I had trouble doing mailing lists via email
before.

Thanks,
Frankie.