Can Messagestats report on emails being received relating to secondary SMTP addresses?
Currently, MessageStats has a report called the Internal Namespace Distribution, which presents the number of messages coming into the Organization from the Internet, grouped by the domain name of the recipient address. This report simply provides an aggregate total and not the addresses that sent to that specific domain name.
When a message is sent to a non-primary SMTP address of a mailbox, Exchange will lookup the primary SMTP address of the mailbox and use that address in quoting the activity of that mailbox in the Exchange Tracking Log. The down side of this is that the original address is not available in the tracking log reports.