Update CHANGELOG.md (#2238)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: community-scripts-pr-app[bot]

CHANGELOG.md

@@ -27,6 +27,7 @@ Do not break established syntax in this file, as it is automatically updated by
 
 ### ✨ New Scripts
 
+- New Script: Proxmox Mail Gateway [@thost96](https://github.com/thost96) ([#1906](https://github.com/community-scripts/ProxmoxVE/pull/1906))
 - New Script: FreshRSS [@bvdberg01](https://github.com/bvdberg01) ([#2226](https://github.com/community-scripts/ProxmoxVE/pull/2226))
 - New Script: Zitadel [@dave-yap](https://github.com/dave-yap) ([#2141](https://github.com/community-scripts/ProxmoxVE/pull/2141))