Proxmox has released Proxmox Mail Gateway 9.1, introducing client-side encrypted backups, deeper spam analysis visibility, and privacy-focused email security features for enterprise users.
Proxmox Server Solutions has released Open-Source Proxmox Mail Gateway 9.1, adding client-side backup encryption, enhanced spam analysis, stronger privacy protections, and tighter integration with Proxmox Backup Server.
The most significant addition is client-side backup encryption, enabling backups to be encrypted before leaving the system. Key management is handled directly within the application, while an optional master recovery key can be stored for recovery purposes. Administrators can also initiate backup verifications and monitor the encryption and verification status of individual snapshots.
The release also improves spam investigation by displaying both the positive and negative components of a spam score simultaneously within the quarantine interface. The added visibility is designed to help administrators understand why messages are classified as suspicious and accelerate threat analysis.
To strengthen privacy and security, external images in quarantined emails are now loaded only on demand through a “Load images” button. This helps reduce tracking-pixel risks, prevents automatic IP-address disclosure, avoids confirming active email addresses, and limits exposure to potentially malicious external content.
For teams managing shared mailboxes, quarantined messages can now be marked as “seen”, helping prevent duplicate reviews of suspicious emails.
Proxmox Mail Gateway 9.1 is built on an updated open-source software stack comprising Debian GNU/Linux, Linux kernel 7.0, OpenZFS, ClamAV, SpamAssassin, and PostgreSQL.
Available immediately under the GNU Affero GPLv3 licence, the software can be downloaded and used free of charge.
