I signed up for the online yoga challenge, but I'm not receiving the daily emails.

If you are not receiving the daily challenge emails, it is likely that 1). you did not complete the signup process to participate in the challenge, or 2). the emails went to your Spam or Junk folder.
If you have only received certain daily emails, this would confirm that you've successfully signed up for the challenge. It is possible your email has put them in your Spam folder or Promotions tabs (for Gmail). Please check these places for our emails. Also, to ensure our email delivery to your email account, please add myyogaworks@yogaworks.com and yogaworks@yogaworks.com to your contact list. 
For Gmail users, here is how to add MyYogaWorks to your Safe Sender list:
  1. In Gmail, select Actions from the toolbar at the top of the screen.
  2. Select Junk E-mail.
  3. Select Junk E-mail Options.
  4. Click the Safe Sender tab.
  5. Click Add.
  6. Type in the email address you wish to add to your safe sender list.
  7. Click OK.