General :: Evolution - Changing Account Information, Imports, And "keyrings"?

I just set up Ubuntu on a computer for my wife today. My first attempt at a working system rather than just a demo. For certain reasons, afterwards I found it necessary to change passwords in the Evolution account. There does not seem to be an obvious way to do this from within Evolution. A bit of "guru" level advice says that something has to be deleted in some "gnome" directory, presumably on the occult command line level of business - but this was a several-years old msg and perhaps Evolution has "evolved". At my newbie level, I am afraid to do anything like deleting things in directories I don't understand.

Also, is there a way to import mail from Outlook Express .dbx folder files? Wife has thousands of valuable emails on her defunct WinXP computer. Finally, at one point Evolution asks for a "keyring password". Not only do I not know the password, I have never heard of the "keyring". Looking this up with a search engine gives an incomprehensible (to me, a newbie) explanation. Can I ignore this? Is there an explanation of why this heretofore unknown bit of Ubuntu arcana should surface? I thought Ubuntu was the Linux for the "rest of us". Should I just junk Evolution and install Mozilla Thunderbird? If so, is there a way to import the emails my wife has downloaded (733 at last count) from Evolution into Thunderbird?