windows live mail...
integrated in Windows OS (Win7) nicely when set as default.
has options within program itself and more customizing when logging into live web site including floating profiles,
all you have to do is log into windows live, works great with (windows) smartphone.
syncs w/ my phone when connected to unit (touch pro 2).
and all the main features of outlook express and windows mail.
Windows 7 does not come with an email program as previous versions of Windows did. You'll need to install an email program from a different company or you can download the new 2011 Windows Live Mail which was just recently released - http://explore.live.com/windows-live-mail?os=other
I've also seen people in this forum say good things about Thunderbird.