Email notification cache?

We imported a large amount of work items (50k+), and wanted to avoid email notification to our users, so we temporarily disabled email notification for one week. After the import, we turned on email notification and our users were blasted with emails every 15 seconds. We quickly turned off email notification (some users received 250+ emails).
We are worried to turn email notification back on in case users continue to receive emails. Is there some sort of email notification cache we can delete? Is there any email notification expiration?
Any advise is welcome... Thanks!
Accepted answer

I also received the following information:
It looks like changes in CLM 6.0 take change event processing more seriously (such as email notification). Two methods can be used to work around this:
- Use a simple SMTP mail sink that eats all notifications from the JTS
-
Use a sendmail milter to filter only the notifications associated with the target project. This takes more work to set up, but it provides that advantage that notifications for other projects and applications are sent.
https://opensourcehacker.com/2013/04/26/debug-smtp-server-one-liner/