If you're looking for an excellent, free mail client, you'll do well to install Windows Live Mail 2011. This newest version of Microsoft's free e-mail client has been significantly upgraded over the previous version, and now includes a host of new features, including a calendar pane and Microsoft Office's Ribbon interface. It doesn't include all the bells and whistles of Microsoft Outlook, such as tasks and a full-blown calendar, but given that it's free, Windows Live Mail is well worth the download.
The new Ribbon puts all of the software's capabilities within easy reach. Ribbon-haters will not be pleased; everyone else will be grateful for it. Another big addition is Conversation View, which was first introduced in Outlook 2010, and has now been ported over to Windows Live Mail. With it, you can more easily follow threaded conversations in which multiple people participate. Whenever there an e-mail has follow-ups, a small triangle appears next to it. Click the triangle, and you'll see a chronological list of every message in the conversation. You can then click any message to jump to it.
Windows Live Mail doesn't just take features from Microsoft Office and Outlook; it gets some from Hotmail as well, including the ability to share photos with other over e-mail by creating a photo album. It's easy to do: Create an e-mail, click the photo album icon, and then select your photos. Windows Live Mail puts thumbnails of them all into a nice-looking photo album in your e-mail. But it doesn't actually send original pictures. Instead, it stores them on Windows Live Skydrive, Microsoft's free, cloud-based storage service that offers 25GB of free space. Recipients of the mail click thumbnails, and are then sent to get the original images on SkyDrive. In that way, you don't clog up people's mailboxes with large attachments.
Also useful are Windows Live Mail's Quick Views, which will be welcomed by people who use multiple e-mail accounts. You can, for example, see all of your unread mail from all of your e-mail accounts, in one location.
All in all, Windows Live Mail 2011 is an excellent upgrade to the previous version of Windows Live Mail.
Note: During the installation procedure, you'll be asked if you want to install the entire free Windows Live Essentials package, or just Windows Live Mail. Windows Live Essentials includes many other pieces of software, so you should only install those components you plan to use.