Update (8/14/2007, 08:49 am PDT):
This has been fixed. Emails are being sent promptly now. However, please note that you have to request or send the required emails once again.
Monday, August 13, 2007
SYSTEM ALERT: System emails aren't being sent
RESOLVED: We're experiencing an issue with our mail server so you may not receive any emails that you request from our system. This includes confirmation emails, private messages, lost usernames and passwords, subscription updates, group invitations, updates to accounts, and sharing videos. We're working on resolving this issue as quickly as possible and will update you when this is fixed. Thank you for your patience and understanding.