emailing
 

How may stop recieving email notifications of a reply to a post?

MyLQ -> List Subscriptions -> Tick all the threads you don't don't to be notified for, then down at the bottom in the "Selected Threads" option box select "No email notification".

Will it take care of future threads?

Yes. THat setting is for future threads. To unsubscribe from threads you've already subscribed to, just go to subscriptions and remove them from the list.