How can I trigger an email+attachment from the browser?

This is for a company intranet app, so everyone is using firefox on XP and I can install whatever is needed.

We'd like to setup an email with a pre-made subject and attachment (similar to using mailto), but the mailto spec doesn't allow attachments.

Any ideas how it can be done? Perhaps using a ff extension?

update: The file is a network file at the company.

update: A good deal of customisation happens in each users outlook, signa开发者_运维百科tures etc. that we'd like to keep.

You're probably much better off providing a form for the users to fill out and and doing the email from the web server. That will give you the most flexibility.