I've worked at a number of places over the years, with a ton of good folks, many of whom I consider friends. I keep in touch with just about all of them, via your typical social networking channels, but also directly via email. (After all, email is in my blood.)
A number of those friends aren't really active with email outside of work. I can't say that I blame them. When spending more than forty hours a week slinging email messages back and forth to pay the rent, not everybody is going to relish the thought of going home, sitting down, and logging on...to send and receive more email messages.
But, what about situations where you want to have a personal email address? It's always a really good idea to have a personal email address, and make sure your friends know it. You might leave your job tomorrow, or three years from now. But, maybe you're not good at checking into a web mail account, and you just want to use your one usual email reader, Outlook or something.
So, why not do this? Create a Gmail account, and consider that your personal email address. In your Gmail, account, click on “Settings” and then click on “Forwarding and POP/IMAP.” Under forwarding, select “Forward a copy of incoming mail to” and set the address to your work email address. Archive Gmail's copy or not, that's up to you. (It just hides it from view; it doesn't delete it from Gmail.)
So, what does this do? It means that whenever somebody emails you to your personal email address, it will be forwarded to your work address. A copy of the mail will also be kept in your Gmail account. You can reply to your friends or what have you from your work email address account, and everything will just work out. (Your replies won't be archived in Gmail, unless you CC your Gmail address.) Or, you can let that email alert you to go log in to Gmail and reply there instead.
Sure, this means that your employer can read your personal email, at least any email sent to this Gmail account that gets forwarded to you at work, but you were probably already sending personal emails from your work email account already. Light use like this is hardly likely to be frowned upon, and as long as you aren't planning anything illegal, or doing anything stupid, I have a feeling your employer doesn't really care who you might be planning to meet up with for beers on Thursday night.