Delete messages from Mailbox, Exchange 2010

Hi, im Alexis from Argentina, i need to delete an email from one mailbox in Exchange 2010 RTM and im getting this error: "positional parameter cannot be found that accepts argument '-deleteContent'." when running

Search-Mailbox -Identity "XX XX" -SearchQuery Subjet:"XXXXX" -deleteContent

Does anyone know why im getting this error?

Thanks!