We've been sending email (as an email service provider) for nearly 16 years at Wildbit. Arguably the most confusing aspects of email delivery is bounce management and SMTP response codes. If you're unfamiliar, ISPs (like Gmail, Office 365) will send SMTP responses back about the success or failure of the messages you send. Oftentimes, these codes can be cryptic and difficult to decipher.

To bring more clarity and accuracy to SMTP responses, we just launched the SMTP Field Manual to be a one-stop resource for understanding all SMTP error codes from all the major inbox providers.

We also wanted to let you know that we are on Product Hunt today to spread the word about the Field Manual. We’d love for you to take a look and show your support!

Security upgrades to SMTP sending (action may be required)

We wanted to let you know about a few changes we’re making to SMTP sending in the coming weeks to make this endpoint more secure. These changes will only affect sending via SMTP. If you use only the Postmark REST API to send, no further action is required on your part.

The most significant change, which might affect you, is that we are disabling TLSv1 on December 14, 2019. This protocol is old and vulnerable, so we will be rejecting connection requests that use TLSv1.

Details and how to update your application →

Template comparison tool improvements

Our template comparison tool now lets you review code changes and quickly navigate between templates. This tool is available when pushing templates between servers.

The Complete Guide To Non-Sucky SaaS Transactional Emails →

Val Geisler wrote this incredibly detailed and helpful guide with 23 examples of effective transactional emails, and what you can learn from each of them. This is definitely a resource to bookmark.

2019 State of Email Workflows →

The Litmus 2019 State of Email Workflows report is out, and provides a comprehensive look at how email marketers get email campaigns out the door, from pre-send planning to cross-channel integration.

Dark mode in HTML email →

Another really useful resource, this one on how to create dark‑mode‑friendly HTML emails. It also includes a handy table on how different email clients handle dark mode email.

Until next month — happy sending!
Rian