Please don't resurrect ancient threads - this one was last active nearly 6 years ago.
For the general answer to your question, see
Split Merged Output to Separate Documents or, better still,
Send Mailmerge Output to Individual Files in the
Mailmerge Tips and Tricks 'Sticky' thread at the top of this forum:
https://www.msofficeforums.com/mail-...ps-tricks.html