Could e-mail notification about watched topics be optional?

I have several threads that I got on my watch list, but don't want to receive e-mail every time someone replies to one of these threads.

Please make this optional.

When you watch a topic for replies you will get an email whether it's just a thanks or a new post. The system can't distinguish between what is posted, only that there has been a post.
If you don't want the emails, then just unsubscribe from the threads. The option is at the bottom right of your screen for each thread.
It will either be "Watch this topic for replies" or "Stop watching this topic".

Too bad. I want to watch these topics, but I don't want e-mail notifications. I got a bookmark to the watch list.