Sometimes all you want is a really simple HTML email template. Here it is.
Preview: http://leemunroe.github.io/responsive-html-email-template/email.html
Use the template as is. They'll put the CSS inline for you when you put together your campaign.
For an API like Mailgun you need to put the CSS inline. You can use Premailer to do this automatically.
- Copy all of email.html
- Paste the HTML as the source into Premailer
- Copy the HTML results and use them in your email view/template
Note that some services may allow you to opt into CSS inlining, such as Mandrill.
Tested on all major email clients. Mobile, desktop and web.
Hat tip to Zurb's Ink for their awesome collection of email templates, which this was adapted from.
Another few open-source resources you might find useful: