yep, that's my question. can I just create any .html file with html/css/pictures/links, and insert the code into an email using an email client (in my case, Apple's Mail.app on MacOS X Tiger 10.4), ...

Email started as a way to send a file between early internetworked computers with little checking about who was sending what. Despite the 60-odd years that have passed, that’s more or less what ...