Open pdf in client application by clicking on the link from the email

Hi,

How can I change the behavior of opening the pdf documents in browser instead of the client applications.

I'm sending an email to the users to direct them to the pdf document and I need the checkout/checkin

options. Right now, when they click on the link from the email - the documents just opens in the browser.

When the go directly to the document library and open the document from there, the document opens in Adobe

Reader, asking for checkout.

I've changed the settings of the document library that stores these pdf documents to "Open in client application",

but this doesn't help.

Thanks