is it possible to write a webapp that can download mails from exchange server 2007

It does not matter what programming language. C开发者_JAVA百科an anyone please give me an idea if this is possible and any tools or API's available please?

Given that you used the imap tag, I'm assuming that means that you have IMAP access to the server. In that case, then yes. There are several third-party components available that provide IMAP access in .NET code. I have personally used RebEx Secure Mail for .NET, and they provide a trial period where you can try it out and see if it will work for your purposes. There's also a fairly helpful help site.

For something free, try this: http://interimap.codeplex.com/