[meeting] 2026-11-04 core mailer beta planning

The merge request in #3539651: Introduce email plugins is finished, issue summary and change record are up-to-date. The group tries to identify potential review-issues by going through the core gates together. The Documentation, Performance and Testing core gates partially apply to the MR.

The core gates in the documentation group are largely met. To help reviewers test the changes hands-on, the example sandbox needs to be updated to work with the current MR. Also clear step-by-step instructions on how to test the new API with existing code will help with reviews.

The mailer is not in the critical path. Performance matters in very specific scenarios. E.g., when sending out a newsletter. It probably is not straight forward to produce a meaningful profile though - considering that many factors will influence resource usage (html rendering, caching, transport, etc.)

A code coverage report would help with assessing whether testing core gates are satisfied. Also existing tests could be converted to the new API. If that works well, we could be more confident that important use cases are covered well with the approach.

The group agreed that it would be a good time to reach out to maintainers of most used mail related contrib modules now. During the discussion about contrib modules it was pointed out that SMTP Authentication Support module provides a unique health check feature.

What’s next:

• Async communication in Drupal #symfony-mailer slack channel.
• Next planning meeting takes place: December 2nd 2026 at 4PM UTC+1 (CET).