Can you please recommend me Books/Ebooks on the Email and things around it?<p>Principles of how it works, how servers connect to each other, security, extensions, implementation details, programming services around Email.<p>I diligently searched on the web and google, but only found Programming Internet Email which seems to be quite old.<p>There are tons of books on topics like JavaScript, Databases, Python, and so on, but no books on email?<p>Also, I'd like to hear opinions if you think that can email be sexy and viable as a basement for a startup these days? I find email the only tool that have been with me for years and I am sure will be with me for years ahead.<p>Please advise and share your opinions.