A new Hotmail feature called "Active Views" is designed to help with just this problem. It recognises specific links from associated partners -- YouTube embedded video links, Flickr photo links and yes, courier tracking codes, and automatically embeds the linked content into the body of your email. So the sender pastes in a link to a web service, and you get to see the content without the need to hit up the website -- the web is brought to your inbox! For me, that means if I want to know where my parcel is, I just check my inbox.
There's a great video below which briefly demonstrates how Active Views works: