Some of the changes in XF 2.2.15 include:
- Avoid setting duplicate List-Unsubscribe headers.
- Include first post QA schema items unconditionally.
- Make outdated PHP version notice in admin control panel clearer.
- Retain the original unsubscribeEmailAddress option for backwards compatibility.
- New unsubscribeEmailHandling option to replace the new unsubscribeEmail option and conclusively fix issues arising from yesterday's XF 2.2.14 release.
- Fix URL unfurls no longer unfurling.