Advance Intellect, developer of the recognized aspNetEmail .Net component, recently released a new component to they're email suite, List Nanny .Net. While the name is pretty lame the functionality is pretty cool. It can determine if an e-mail is a hard bounce (i.e. an e-mail that has bounced back due to a wrong address), an out of the office notification, a spam notification, or several other types.
So what makes this interesting? Well by integrating List Nanny .Net with their aspnetPOP3 component you can develop a simple app that retrieves all of the mail out of a specified account, looks for bounced mail, then does some processing based on the bad address (it returns that too). We're in the process of integrating this functionality into our custom membership system. Whenever an e-mail bounces back we'll mark the address as 'invalid'. This will allow us to follow-up with the individual with a postcard that asks them to update their address on-line.
With the size of our church e-mail becomes the number one way we can communicate with our members. Yet e-mail addresses change so frequently (especially among youth). With this quick solution we can remain on top of changes quickly.
If it sounds like a lot of work it's really not that bad. My initial sample app is only 50 lines of code and took no more that 2 hours to write. Definitely worth the effort.