Export Message Tracking Log for a Specific Sender after a certain day

Scenario: Export the message tracking log for a specific sender after certain day to a .csv

Get-TransportServer | Get-MessageTrackingLog -Sender user@domain.com -Start 3/19/2014 | Where EventID -like "Send" | Select MessageSubject, ClientIP, ClientHostname, Timestamp, {$_.Recipients} | Export-csv C:\users\username\desktop\messagetrackinglog.csv

Note: the Recipients is enclosed in {$_. }. This is because the recipients property is an array that can hold multiple values and it does not export correctly if referenced without the additional formatting.