I am working with a personalised web 2.0 portal that has number of widgets, I would like to write a widget to display last 4 email Subjects from a userís inbox, so mainly I have 2 questions:

1. I will authenticate the user in my web portal, so how can I authenticate with Zimbra (without asking the user to re-enter credentials), also I want to retrieve last 4 emails from the userís inbox (preauth URL will not help me in that scenario, as I only need to display last 4 emails subject not to eredirect the user to his inbox).

2. Is there a way that I can reset \ change userís passwords from a third party application (i.e the web portal I have mentioned earlier)

I am using C# ASP.NET 3.5, If am going to use the SOAP interface for Zimbra, I am assuming that I can build a proxy using .NET, but how can I download Zimbraís WSDL

Any help is much appreciated,