mp, you do that via "subscriptions" ~ and you get to "subscriptions" by clicking "Account" in the upper left corner next to your name, then clicking on "notifications" ~ that's where you'll find "subscription" options ~ here's how yuku's "how do I ..." site explains it ~ Sooz
From Yuku Help
You can subscribe to email updates on message boards, blogs and profiles. If you just posted on a message board and you want to get an email update each time there is a new post on that thread, forum or board you can easily do so by using the email subscription feature.
The notifications page is where you can manage the communities, blogs, forums and topics that you have subscribed to.
How to subscribe
Every community main page, forum page or topic page should include two icons for notification. (These icons can be changed by the board admins, so they may look different on different communities.)
This is the icon for RSS Feeds (news feeds) When you click on the rss icon you will get a url to use in a news reader program. Some Browsers can show the rss as text within the browser. Read more about how to use this in RSS Feeds.
This is the icon for email notifications When you click on the email icon you will be asked to confirm that you wish to subscribe.
If you click on the icon on the main page, you will get notification for each new topic on the whole board.
If you click on the icon a forum page, you will get notifications for each new topic in that forum.
If you click on the icon in a topic page, you will get notifications for each new reply in that topic.
Notification Subscriptions
Once you have set up some subscriptions, you can remove them at any time by going to your Notifications page (navigation > settings > notifications > Subscriptions)
Notification options
(navigation > settings > notifications > options)
You can choose to get emails for every single new item, or to receive a daily digest instead on the notifications options page.
On this page you can also set whether you get an email to alert you of new friends, pms, and profile comments. (please note, this image says image comments, but it's actually profile comments.)