My email situation is quite scattered now. I have a Yahoo! Mail account and a Gmail account. I have the Gmail account set for both POP forwarding and for IMAP. The IMAP is just for experimental purposes. I access the Gmail either way, by webmail or with my email client.
My primary is account is with my ISP. I can access it either way but usually use an email client to get it as POP mail.
Regarding email clients, I have my main email account (with my ISP) set up in three different computers but I use Outlook Express in my Windows XP system as my primary location for saving POP mail messages. I also have my ISP email account and a website email account set up in Outlook 2003.
On my laptop, I use Windows Mail but also have my email account set up in Outlook 2007. And, I have another desktop system running Windows 7 RC and have my ISP email account set up in Windows Live Mail.
With Windows Mail (on laptop) and Windows Live Mail on the Win 7 computer, I have the email client set to leave messages on the server. That way, I can still retrieve all mail in Outlook Express, which is set to remove messages from the server after downloading.
I have also used Evolution, the default email client in Linux Ubuntu, and Thunderbird, also with Ubuntu.
Why all this email activity? Well, it's really just to be familiar with the various email clients and webmail services so that I can provide support to other users when they have email questions.