I would like to be able to process incoming emails for a particular account. Things like parsing subject/body, process/save any attachments, upload processed data to a database, etc.
Another thing I have seen at one firm I worked at that I would like to be able to replicate, is setting up an email account that processes the subject of incoming emails and send the appropriate response back. For example, I send an email with the subject line "sales/NY/2010", the process recognizes the format, runs the appropriate query against a database, and sends back an HTML-formatted email with a table with the corresponding data.
Is VSTO the proper tool? I'd like to have a clean solution, server-side, so I don't have to resort to running an app/service that periodically polls the inbox of a particular account for new items.