Debian 13 VM with Proxmox Mail Gateway 9
by cloudimg
Email security gateway that filters spam and viruses before mail reaches your mail servers.
Proxmox Mail Gateway 9 on Debian 13
This virtual machine runs Proxmox Mail Gateway 9.1, the open source email security gateway, on Debian 13 trixie. It sits between the internet and your own mail servers as a full mail proxy: every message is scored by SpamAssassin with Bayesian filtering, DNS blocklists, SPF and DKIM checks and greylisting, scanned by the ClamAV antivirus engine, and handled by an object based rule system before it is relayed on. Administrators get a web interface and REST API, a tracking center that follows each message, and a per user spam quarantine with daily spam reports. The software is installed unmodified from the Proxmox repository, and the virtual machine keeps the Debian cloud kernel.
Secure by default
No login is baked into the image. On first boot each virtual machine creates its own web administrator with a random password in a file only root can read, and generates its own web certificate, API signing and CSRF keys, SMTP TLS certificate and database TLS key. Antivirus signatures are downloaded fresh on first boot. The gateway relays mail for no domains until you add yours, and its internal relay port only accepts your own network.
Ports, sizing and Azure mail rules
Inbound ports are 25 (mail from the internet), 26 (outgoing mail from your mail servers), 8006 (web interface) and 22 (SSH). Standard_B2ms (8 GB) or larger is recommended for production. Azure blocks outbound TCP port 25 on most subscription types except Enterprise Agreement and MCA-E, so the guide explains relaying outbound mail through a smart host on port 587 and delivering to mail servers you reach privately.
Licensing and support
Proxmox Mail Gateway is free software under the GNU AGPL v3. The cloudimg charge covers packaging, patching, image maintenance and 24/7 support; Proxmox subscriptions are available separately from Proxmox. Proxmox is a registered trademark of Proxmox Server Solutions GmbH. This image is built and supported by cloudimg and is not affiliated with, sponsored by or endorsed by Proxmox Server Solutions GmbH.