This will probably get a lot of hoots and hollers, but I have had decent luck with WLM (Windows Live Mail). It will want to install Windows Messenger, Bing Bar, etc., but you can just chose "custom install" to pick and choose what you want.
I have email accounts from 4 different server/domains and it works well (saving your login credentials) with all of them. Do note that it "plays" better with POP3 accounts than with IMAP. I also use it to manage my newsfeeds. It has a lot of features for being free.
The only bugs I have seen are: "sometimes" feeds do not update automatically (just chose "sync feeds), and every once and awhile black bars will show up (restarting the app clears that up). These are known bugs in all the tech forums, and I do not believe there will be another release until WIN8.
All free clients will leave you wanting more. And the free clients will start disappearing (IMO) as everyone wants you to move to web-based clients and cloud storage. Another alternative (c'mon with the hoots) is to get the full Outlook program. Look for a cheap Office or a stand-alone Outlook on eBay. Last time I checked, you could get a Outlook or bundle for $99-$109 retail.
I used the full Outlook, years ago, but quit when I upgraded my O/S and MS stopped support for VBA. Office 2010 has support for VBA again, so I might give it another try.