looking to delete from exchange 2010 where subject line contains Transaction and has a pdf as attachment

[PS] C:\Windows\system32>get-mailbox -resultsize unlimited | Search-Mailbox -SearchQuery 'Attachment:"*.pdf" Subject:"*transaction*"' | export-csv c:\temp\trans.csv

Sending data to a remote command failed with the following error message: Cannot access a closed Stream. For more information, see the about_Remote_Troubleshooting Help topic
    + CategoryInfo          : OperationStopped: (System.Manageme...pressionSyncJob:PSInvokeExpressionSyncJob) [], PSRemotingTransportException
    + FullyQualifiedErrorId : JobFailure
    + PSComputerName        : lncexc001.internal.bloodservices.ca

I want to query subject: contains *Transaction* and also contains an attachment *.pdf

Then delete