How can I tell if a sent hotmail has been opened?

This is simple! When I send an email on Hotmail, how can I tell if the message has been picked up by the recipient?

Are you referring to read receipt? 

It is a response from an e-mail recipient that indicates the message was opened. The read receipt has to be requested by the sender, and the recipient may or may not comply. Is it is, I'm sorry but the read receipt option is not available in Windows Live Hotmail.

Please follow these steps, as a workaround, you can use Windows Live Mail to use this feature.

• Open Windows Live Mail.
• When composing a new message, go to Tools -> Request read receipt.

If you don't have Windows Live Mail installed yet, you may download it from here.