Getting this error in the logs when user email is not defined:
#0 /var/www/html/web/core/lib/Drupal/Core/Mail/Plugin/Mail/PhpMail.php(123): Drupal\Core\Mail\Plugin\Mail\PhpMail->doMail(NULL, 'Your account wi...', 'Dear User,\n\nYou...', 'MIME-Version: 1...', '-<edited>...')
#1 /var/www/html/web/core/lib/Drupal/Core/Mail/MailManager.php(308): Drupal\Core\Mail\Plugin\Mail\PhpMail->mail(Array)
#2 /var/www/html/web/core/lib/Drupal/Core/Mail/MailManager.php(181): Drupal\Core\Mail\MailManager->doMail('purge_users', 'cancel_users', NULL, 'en', Array, NULL, true)
#3 /var/www/html/web/core/lib/Drupal/Core/Render/Renderer.php(593): Drupal\Core\Mail\MailManager->Drupal\Core\Mail\{closure}()
#4 /var/www/html/web/core/lib/Drupal/Core/Mail/MailManager.php(180): Drupal\Core\Render\Renderer->executeInRenderContext(Object(Drupal\Core\Render\RenderContext), Object(Closure))
Investigating.
Active
4.0
Code
The code seems simple and correct. I've used the MR for a patch and it's working correctly.