Enhance custom bulk email component of an existing C# Web App -- 2

We have an existing ASP.NET Web application in production with a custom instant bulk email feature that our clients are using and have been using (last year we sent 100,000 emails) with a lot of success. This job is to enhance the instant email component of our system to increase the features usefulness. The basic workflow: When field data (typically door to door surveys 1st/last name, basic demographics email along with some client defined questions) is submitted to our web server (ASP.NET) from one of our mobile devices AND when the clients environment is setup to do so, we'll send an email out based on an email template to whatever email address was provided in the field data. Email templates are created and maintained using our email template tool which is integrated into the same web app. We would like to improve and expand on the tool that users use to create the template that's used to create the emails that are sent out. We use SQL Server 2014 /w NHibernate to store/persist all data(email addresses, email template). Here are the details of what we need done. NEW WORK: This job is to specifically add the ability to add sometimes encrypted, always zipped attachments to emails. In addition, when the user selects a PDF as the attachment file, the system shall inspect the PDF and possibly set some form fields based on the information filled out by the user in the field. I will provide a database with sample data, and easy method to reset the data, sample PDFs and pointers into our code based on where to look to add in your code. Feel free to read the PDF and ask specific questions to clarify before or during your bidding process. I would like to have the 1st version of your code reviewed and tested by 3/13.