Cheat
Authentication Cheat Sheet
There are a several approaches to authenticating email, and the different authentication methods have a lot of different settings to choose from (sometimes because they’re useful, other times just because they were designed by committee). It’s nice that they have that flexibility for the complex situations that might benefit from them, but almost all the time you just want to choose a good, default authentication approach.
So here’s some short prescriptive advice in no particular order for “how to do email authentication at an ESP well” without the long discussions of alternative approaches and justification of each piece of advice.
Multipart MIME cheat sheet
I’ve had a couple of people ask me about MIME structure recently, especially how you create multipart messages, when you should use them and which variant of multipart you use for different things. (And I’m working on a MIME parser / generator for Abacus at the moment, so it’s all fresh in my mind)
So I’ve put together a quick cheat sheet, showing the structure of four common types of email, and how their MIME structure looks.