I'm still in the prototype phase of a project with the same problem, and it's the one aspect of it that makes me nervous. Note that you don't always need to st

I'm still in the prototype phase of a project with the same problem, and it's the one aspect of it that makes me nervous. Note that you don't always need to store the password - GMail will let you do IMAP using OAuth, and Yahoo has their Mail Applications. My own plan is to launch with support for those and find out a little about demand for the product before we start storing people's passwords.