Virtual machines
Outbound email (SMTP)
Outbound SMTP is blocked at the network edge by default. How to request an unlock.
Outbound email from instances (SMTP on ports 25, 465, and 587) is blocked by default at the hostd network edge. This applies even when Proxmox VM firewall rules allow the traffic.
We do this to protect the reputation of our IP ranges.
Status in the portal
On VM → Firewall you see whether outbound email is Blocked or Allowed for that instance.
Request an unlock
- Open VM → Firewall.
- Use Request unlock.
- Describe the purpose, the sending domain(s), and the expected volume.
- Submit — a support ticket is created. You can follow it under Support.
We review the request (typical checks: legitimate use, domains, account history). After approval, outbound email is unlocked for the instance.
Watch out
- Unlock is per instance / its public IP(s). If the public IP changes, contact support so we can update the allowlist.
- Guest or Proxmox firewall rules alone cannot open outbound SMTP while the edge block is in place.
- Configure SPF, DKIM, and DMARC for domains you send from.