Just a quick update to let anyone that has been following this know that I have not forgotten about this project. I have been working on it again today and have made some good progress – my code can now correctly parse the response sent from a DNS server for an MX lookup. So now I just need to do some more testing (and tidy up some of the code) and then I can move on to the task of actually transmitting an email from my application to another SMTP server.
I have to say I am looking forward to working with the SMTP protocol again rather than DNS as it will be nice to just be using text again instead of bits and bytes!
Will hopefully have some more news on this quite soon and it will not be too long before it is ready for BETA testing.