For this report one would need to have enabled Mailbox Auditing for all mailboxes in the Organization for the specified period of time.
Such a large Mailbox Auditing is not however really recommended unless it's done in batches and only while monitoring the effect that such gathering can have on the size of the SQL database as well as any overhead during the gatherings on the Exchange/MessageStats servers.
After such a gathering is successfully completed one can run a custom report based on the "Mailboxes - Mailbox Auditing Messages Received" data source. This report can be filtered on the date and the originator (SMTP address of the external sender).
