v2.1.2: Slack if wp_mail_failed

🚀 Feature

• Slack Alerts for Mail Failures: Receive Slack notifications when wp_mail fails
  • New "Slack Webhook URL" field in plugin settings
  • Alerts include site name, recipient, subject, and error details
  • Uses WordPress wp_mail_failed hook for reliable detection

Full Changelog: v2.1.1...v2.1.2