Remove attachments over 45 days

Hi team!
I apologize for my English :)
I am using Exchange 2010.

So.. I have a problem...
My main task to remove attachments from mailbox older than 45 days.
Read the discussion forum Microsoft and not only.
Tried expert advice:

$mailbox = "Mailbox"
Search-Mailbox -Identity $mailbox -searchquery '(sent:06/01/14..07/31/10)' -DeleteContent -force

Search-Mailbox -Identity $mailbox -searchquery:<06/01/14 -DeleteContent -force

New-MailboxSearch -Name "MailboxName" -StartDate -EndDate -TargetMailbox
Search-Mailbox -Identity $mailbox -searchquery attachment -DeleteContent -force
and many other tips...

But i'm not have been able to solve the problem.