Hi,
I have a lot of experience with wireshark and winpcap and I've already written applications like this one. I also have some experience with LUA, the scripting language wireshark uses should the need arise. I've also extensive network programming experience in various languages ranging from C to Python and I used Wireshark on a daily basis for several months.
However I am not 100% sure about the scope of your project. Does this involve writing the receiving HTTPS server as well? From what I understand, you have 3 parts, the packet capture and filtering, the https upload and the smtp sending. All of this should be easy to deal with in C#. Also if you could clarify what kind of filtering you want (ip:port or deep protocol analysis), it would help me get a clearer picture.
I hope you will consider my bid.
Eric