Over the past year, tweetymail has sent and received hundreds of thousands of emails. While we've gotten more sophisticated at processing emails, we've kept the (internal) format of the emails we send the same since Day 1: HTML only, UTF-8 encoding, and not much else.

I've always wanted to rework our email format to be more complete and consistent with email messaging guidelines, but for the most part, the emails seemed to be working just fine. We tested with every every major email client we could get our hands on: GMail, Yahoo! Mail, Hotmail, Lotus Notes, Microsoft Outlook, Apple iPhone, and BlackBerry. The emails displayed correctly in all of those clients so why mess with a good thing?

Well, it turns out that some email service providers - not email clients - had a problem with our format. Even though our emails passed spam checks, certain email providers were intentionally "breaking" the message - as a security measure - to prevent the HTML from displaying correctly. After hearing about this from a handful of users yesterday, we knew the time had come to make some changes.

Last night we started sending emails using a completely new format. The appearance of these emails remains the same, but internally, the new format should fix issues with email service providers and email clients. The new emails also include basic plain text alternatives for completeness. This is in turn means that more users (hopefully all!) should be seeing the emails how they were meant to be displayed.

This is a pretty major change and we are interested in your feedback:

• Did this new format fix email display issues that you previously had?
• Did this new format introduce any new email display issues?
• Have you noticed any changes to the delivery of email from tweetymail? In other words, are emails still reaching your inbox successfully?