Filtering included in every plan
- Spam filtering: adaptive scoring that learns from your corrections, sender reputation checks, public blocklists and greylisting.
- Virus and malware scanning of every message and attachment, on every plan except Micro. The Micro plan does not include antivirus scanning.
- Attachment defence: zip, rar and 7z archives are inspected, including password-protected ones and files disguised by their extension, and you can refuse chosen file types by their extension.
- Phishing protection that inspects content, links and the sender's claimed identity, and checks links against the SpamDuster PhishList.
- Sender authentication: SPF, DKIM and DMARC checks on incoming mail.
- Threat signatures and rules that refresh continuously in the background.
Managing mail
- Blocked mail review: copies of blocked mail are kept, sorted into spam, phishing and virus folders, and can be released by an administrator. See Review blocked mail.
- Allow and block lists per sender, domain, mailbox and IP address. See Allow a sender.
- Log search for every message, with a printable delivery receipt as proof that your mail server accepted it. See Find a message and prove it was delivered.
- Dashboard with mail volume, the spam rate and the top spam sources.
- Alerts by email when disk, memory, the certificate or the filter need attention.
Running the server
- A dedicated server for you alone, on Linode.
- Automatic, signed updates, rolled back automatically if anything goes wrong. See How SpamDuster updates itself.
- A certificate for your server's hostname, issued and renewed automatically, and support for your own hostname. See Use your own hostname for the filter.
- Control panel integration for cPanel & WHM, Plesk on Linux or Windows, and DirectAdmin, which keeps your domain list in sync. See Connect a hosting control panel.
- A number of domains and email addresses set by your plan, with one gateway (mail) server; domain expansion packs add more. See SpamDuster Cloud plans.
Not included in SpamDuster Cloud
- Filtering outgoing mail. SpamDuster Cloud filters the mail you receive. Filtering the mail your servers send is SpamDuster On-Premise Outbound, which is not available yet.
- Mailbox hosting. SpamDuster does not store your users' mailboxes; it delivers to your own mail server.
- Access to the server itself. We run the server; you manage the filter through the console.
Updated 2026-10-31Need help? Open a ticket in the billing portal.