For the love of God please also send a plain text variant of your fucking fancy email if you’re building some web service that needs sending mails. I am going nuts over how many times I wanted to reset a password or read a fucking newsletter 1 and my email client just hit me in the face with a wall of CSS and HTML. I don’t care about your cool formatting and text and pictures or whatever. I read emails. Do you read a photo? Do you read colors? No? Then send me readable shit. If you have to send some other stuff, there is this cool thing I heard about called ATTACHMENTS (not the inline ones).
In the case of password reset emails you just need to give me two links: one for resetting the password and one for reporting the reset if I didn’t initiate it. So two links, two paragraphs (to explain what the links do) and a signature. That’s it. I’m sure your “engineers” are smart enough to figure out how to write a template for your mail to be send as plain text too. Major web frameworks like Ruby on Rails have things to help with this.
Accept the facts: most people don’t care about your newsletter. And if one of the five motherfuckers that do reads their emails in plain text then you better fucking send a plain text version.