MailDeveloper: For Creating Responsive, Bulletproof Emails
I just released my email-related product out of beta, and would love to hear your opinions and feedback on it.
I'm sure many developers who visit these forums are creating amazing, custom templates, but I want to point out that MailDeveloper retains full control on the output HTML. I've been using it myself at work for a while now and had no problems.
Here's also a coupon code for 50% off for 3 months (expires in a week). Hopefully it's not against to rules to post it (if it is, someone let me know and I'll remove): LITMUSFOLKS
Finally, link to the app itself. At least try the free, no-registration demo of the editor: