Do Apple Me.com passwords expire? I am getting a notice I need to reset it or it expires today!

Just got an email that looks like it is coming from the Me.com server.

Why would ANY of my passwords expire????

This is my home computer and account - not associated with a corporate account.

And - NO - I did not click on the link to reset the password.

I signed into Me.com online and don't see any messages there to reset my password.

What is a gal to do????