Hi Customer,
Thanks for your feedback. The issue should have been fixed now, and you can get the detailed information in the Service Health page in the portal. Please check if the email service is working normally on your side. If the issue persists with your tenant, please post a reply in the following thread.
http://community.office365.com/en-us/forums/160/t/75529.aspx
Best Regards,
Reken Liu