You can sign up for Team Discussion Digests simply by heading to your Team profile page on Etsy and clicking the "Subscribe to Team Digest" button on the left sidebar. Each Team has it's own discussion forum so you must sign up for each digest individually. To manage your subscriptions, go to Your Account, click on Settings in the left column and then visit the Emails tab. Scroll down and you will see the "Team Digests" box, where you'll have a list of Teams Digests that you subscribe to. Just check or uncheck the boxes for Digests you'd like to unsubscribe to, then click Save Settings and you're all set.
You can read more about this in NeonMorgan's blog post: www.etsy.com/blog/en/2011/stay-in-touch-with-team-digest-emails/