This will be a quick post.  I was trying to find/remember the syntax to add multiple email addresses to a single “Send a notification email” action and I couldn’t find it documented anywhere. So I tested and confirmed that all that is required is using a “;” between the email addresses as shown below.

Update 3/18/2015:

I’ve just learned that because the vCenter Server Appliance uses Sendmail the delimiter for multiple addresses needs to be a comma instead of a semi-colon.

http://adminafterwork.com/2013/11/14/linux-based-vcenter-server-appliance-vcsa-bug-vcenter-email-notifications-sent-using-multiple-email-addresses-action-sending-notification-emails/