Add "preview template" option for newsletters

[sod]

Maybe Mitch’s workaround could work for you as well?

Solved: How to send a test email to preview newsletter design changes

If you change the custom HTML template for your newsletter, you’ll want a way to preview the results without blasting your subscribers with a janky design. The only good way to do that is to send a test email to yourself only — and maybe a few beta testers — but there is no direct way to do it in Micro.blog. No “send a test message” button. Here’s the workaround, and it’s easy: Just use your free test blog. Set the design of your test blog to be the same as your main blog. Set the newsletter fr…