Go to Adept and search on openoffice. See if openoffice.org is installed. I believe this is the one I installed which also got openoffice-base, the database. It could be that the Envelope is requiring the database to be installed in preparation for looking up addresses. It should not be that way, and may have been fixed by now, but with a fresh install of 7.04 it definitely was a bug.
Go to Adept and search on openoffice. See if openoffice.org is installed. I believe this is the one I installed which also got openoffice-base, the database. It could be that the Envelope is requiring the database to be installed in preparation for looking up addresses. It should not be that way, and may have been fixed by now, but with a fresh install of 7.04 it definitely was a bug.