February 2019 Summaries

In reality, blacklists don't have the power to block messages as widely as people think, and most recipients only reference them during rigorous spam-filtering. Many blacklists are implemented more like flags, with most users taking listings with a grain of salt, and delisting is often automatic after a short time. The influence and reputation of the blacklist can affect how long it remains listed, but even then, just because an IP is listed now doesn't mean it was always that way or will be in the future. To confirm if an issue exists, recipients should pass a note to Postmark support team, which can help assess deliverability trends and investigate potential causes of any affected messages.

Your file size matters when sending emails, especially through ESPs like Postmark, as large messages can lead to delivery issues and even spam filtering.` `Postmark has a limit of up to 10MB for message sizes, including headers and attachments, but larger messages can be flagged for spam by mailbox providers like Apple Mail, Outlook, Google Apps domains, and Yahoo.` `Message size is directly related to email deliverability, with most messages under 100KB seeing the same acceptance rates across all mailbox providers, while larger messages may trigger spam filtering or delivery issues.

The latest update from Postmark brings a fresh design and additional features to their weekly account digests. Starting next week, users will receive a new look with improved statistics displays for outbound/inbound activity, bounces, and deliverability recommendations. The updates aim to provide users with a better overview of their account health and actionable steps to improve email delivery. Key changes include color-coded stats, warnings for high spam rates, and a checklist of tasks to enhance deliverability. The digests will also feature recent blog posts and product updates at the bottom.

Gmail has made significant improvements to its automated filtering in an effort to reduce spam, resulting in a decrease in transactional messages going to the spam folder. However, this change appears to have caused issues with delayed or missing messages for some senders, particularly those using Postmark's transactional-only message policy. The issue seems to be affecting specific senders indiscriminately, regardless of their sending volume or reputation, and is likely due to Gmail's increased focus on blocking spoofing and phishing attacks. To mitigate the issue, customers can wait for Gmail to update its systems and submit examples of affected messages to improve the filters faster. In some cases, changing authentication subdomains has helped Postmark customers get back into the inbox, but this may not be a viable solution for everyone. The impact of this change is currently limited to specific senders, and monitoring engagement rates can help identify if own messages are affected.

The Postmark API is a cloud-based email service that allows developers to send and track the status of emails using Python. To use the Postmark API, developers need to create an authorization token and add it as a header in their REST requests. The API requires a minimum of sender information, recipient information, subject, and HTML body to be included in the request. The `requests` library is used to send the email and get the response from the Postmark API, which can be converted to JSON using the `json` library. Once an email is sent, developers can use the MessageID to check the status of the email by polling the Postmark API with a GET request. This allows developers to track the status of emails, including errors and delivery attempts, and provides valuable information for debugging and support purposes.