A Firefox Plugin

I need a Firefox plugin that will encrypt the content of emails before sending email, and decrypt the content while displaying the content on [login to view URL] website. I have got similar plugins made for Gmail and Yahoo which I can forward in order for your reference and help. The detailed description is provided in the attached file. Some parts of the plugin is already developed and I will be forwarding you the code for those parts in separate modules. The total budget of the plugin was $875 (as you can see in the attached file). The steps 1, 2, 4 and 6 are already implemented for a total worth of $210. So the remaining amount of budget left is $665. Whoever bids $665 or less for the project will be hire immediately. This project is for a trusted client. No payments or milestones will be created until the project is completed, and tested by the client, and until the client is satisfied. Once the project is complete, you will be offered similar jobs for Chrome, Safari and IE plugins as well.