Get-MessageTrace -SenderAddress <user> -RecipientAddress <user> -StartDate <date> -EndDate <date> | Export-clixml c:\temp\MessageTrace.xml -encoding utf8

Get-MessageTraceDetail -MessageTraceID <get the ID from the Get-MessageTrace> -SenderAddress <user> -RecipientAddress <user> -StartDate <date> -EndDate <date> | Export-clixml c:\temp\MessageTraceDetail.xml -encoding utf8

Start-HistoricalSearch -ReportTitle “<meeting subject>” -StartDate <date> -EndDate <date> -ReportType MessageTraceDetail -SenderAddress <user> -NotifyAddress <user>