Deleting a post does not delete all associated comment subscriptions

[raamdev]

A user writes on WordPress.org...

After deleting a few posts I’ve found that the subscriptions are still showing and not being deleted along with the post. Is there an easier way to delete the data? I’ve got 35000 subscriptions so finding them is a long process.

Comment Mail should delete any associated subscriptions when a post is deleted.

Related: #336