[gjolund]

I don't know a single start up that actually builds their own html emails.

It is a part of the industry that has been entirely replaced by services, similar to web hosting.

[blowski]

I freelanced for an ecommerce startup coding all their emails from scratch. Their marketing was built around very dynamic, complex emails that were pretty much impossible to template.

[rgrove]

You do now! I built custom HTML emails for my startup.

[dismantlethesun]

I did. There's a bunch of very good responsive email templates to start off.