Cloud e-mail and portal integration: experiences?

I am evaluating cloud e-mail solutions based upon:

I work for a University and we currently have an institutional portal (based on uPortal).

We currently have our local IMAP server and webmail client fully integrated with the portal. We would like to replicate the current portal e-mail experience with the new e-mail services. At present users can see a snapshot of their inbox in the portal and click through into the appropriate place in the webmail client.

We expect that we need to solve similar problems when integrating with the cloud based e-mail solutions.

We need to solve the single sign-on (SSO) problem.
We need to be able to access the inbox messages on the users behalf. (e.g. proxy authentication)

Does anybody have an experience or advice on this?

Many thanks,

Mark

Solution

Not sure what programming language you can use, however you can download the source code for some MOSS web parts for live@edu to give you an idea how to code them, they use SSO.