This release includes support for our new metadata feature. You may now include metadata with your outbound messages, and Postmark will include that data in webhook payloads, message details, and message searches. See the full release announcement here.
This release also enables you to specify the BaseURL for each API request, making testing with Guzzle a lot easier.
Finally, you can now enable, or disable SMTP API Error Webhooks for Servers using the Admin Client.
As always, we hope this release helps you get even more value from Postmark, and please feel free to contact us if you have any questions or requests!