B.01
Your rules, quarantine and logs belong to you alone; the filter platform is not shared with other customers
Managed Mail Gateway (Proxmox PMG)
Your own mail gateway in front of your mail server. We run a Proxmox Mail Gateway instance in the Netsource private cloud that serves your organisation alone. It filters spam and viruses, your staff manage their own quarantine, and the rules follow your specifications.
01
Your Benefits
B.02
Staff see their held emails and release them without raising a ticket. A daily summary arrives by email
B.03
Every filter decision can be traced, as each email can be followed in the tracking centre through to delivery
B.04
Outgoing emails are signed (DKIM), which protects your reputation as a sender
B.05
Operated in Germany on Netsource infrastructure using open source, with no licence fee per mailbox
02
Service scope
L.01
Dedicated PMG instance as a virtual machine in the Netsource private cloud, backed up daily to the Proxmox Backup Server
L.02
Incoming filtering: spam scoring, virus scanning, DNS blocklists, greylisting and attachment rules (e.g. blocking executable files)
L.03
Outgoing filtering with DKIM signing and sender rules
L.04
Quarantine with a self-service portal and a daily quarantine report to staff
L.05
Rules to your specifications, such as sender exceptions, subject tags like [SPAM] or a copy to an archive or mailbox (always-BCC)
L.06
We switch the MX records in the Netsource DNS Service and make sure your mail server only accepts mail from the gateway
L.07
Updates, current signatures, monitoring and a monthly review of the filter statistics
03
Requirements and exclusions
→ Prerequisites
- Your own mail server (on premises or hosted) or a Mailcow instance as the delivery target
- The mail domain is managed by Netsource (NDS-DOM-DE), or we have access to its DNS for the MX change
- A maintenance contract, if you need a guaranteed response time
✗ Not included
- Mailboxes in Email Hosting (NDS-WP-MAILCOW) already include basic filtering. Your own gateway is worthwhile for special rules, self-service quarantine or an external mail server
- If you want neither your own instance nor any operating effort, MailProxy (NDS-SEC-MAILPROXY) filters mail at the registrar
- If your mail server goes down, BackupMX (NDS-SEC-BACKUPMX) holds incoming mail. The gateway only keeps emails during delivery attempts
- Encryption and signing of individual messages (S/MIME, PGP) is handled by the Secure Mail Service (NDS-SEC-MAIL)
- The gateway does not replace antivirus on your devices (NDS-SEC-AV) or awareness training (NDS-SEC-AWARE)
04
Related Services
NDS-SEC-MAILPROXY
MailProxy
A virus and spam filter in front of your own mail server. Incoming emails are checked in Germany before they reach your system. It is intended for businesses that run their own mail server and do not want to expose it to the internet unfiltered.
NDS-SEC-BACKUPMX
BackupMX
If your mail server goes down, a second mail server accepts your emails and holds them. Once your system is reachable again, it delivers them. Senders receive no error message and no email is lost.
NDS-WP-MAILCOW
Email Hosting
Email hosting with Mailcow in a German data centre, independent of Microsoft. You get a dedicated VM with your own IP addresses, IMAP, SMTP and ActiveSync, and built-in spam and virus filtering.
NDS-PVE-VM
Proxmox VM on Private Cloud
A virtual machine on our Proxmox cluster in Berlin. You choose vCores, RAM and storage as needed, and backup is built in.
NDS-PVE-PBS
Managed Backup
We back up your servers, systems and databases with encryption and monitor every run. Depending on the system, we use Proxmox Backup Server in the Netsource data centre in Berlin or Bacula. You pay per backup job and per GB of data backed up.
Does this fit your business?
In 30 minutes we work out whether this service suits you. Free and without obligation.