You can cancel a merge to disconnect a mail merge publication from its data source.
On the Tools menu, point to Mailings and Catalogs, and then click Cancel Merge.
When asked if you want to cancel the merge, click Yes.
The publication is disconnected from its data source.
If you cancel a mail merge, fields other than Address Fields, Greeting Lines, and Address Blocks are converted to regular text.
If you cancel a catalog merge, the catalog merge area is deleted.