We're on Exchange 2010, and some of our Outlook 2010 users are getting this error below, when sometimes sending to ONLY ONE recipeint:
[Postmaster] Email Delivery Failure
This is a delivery failure notification message indicating that an email you addressed to email address :
[replaced email address for privacy] could not be delivered. The problem appears to be :
-- Bounce - Recipient server condition
Additional information follows :
-- Too many invalid recipients
This condition occurred after 1 attempt(s) to deliver over a period of 0 hour(s).