[Lynne]

You may close your vbulletin site and then your email should still work. Try running these queries, but put a prefix in front of the table if you use one:
UPDATE datastore SET data = REPLACE(data, '"bbactive";i:1;', '"bbactive";i:0;') WHERE title = 'options';
UPDATE setting SET value=0 WHERE varname='bbactive';

If you use datastore caching (a setting in config.php) then you will have to edit that also (or just turn it off since you won't need it with the board off).