You requested it... and we delivered it in Exchange 2010! One of the most requested items in exchange 2007 was something like this... ...we have 5-12 external domains that we need to allow so...
Published Jan 18, 2010
Version 1.0
Blog Post
Pete/Shawn... take a look at the link Dave passed on, as well as http://technet.microsoft.com/en-us/library/dd298094.aspx. Specifically "RecipientRateLimit"... does this meet your need?