Resilient. Reactive. Realtime. Responsive.

The Heluna system is based upon a suite of components custom-built to filter messages.

Multi-stage filtering

Messages pass through multiple services prior to showing up in your inbox or quarantine.

The overall Heluna system is divided into multiple stages that a message passes through prior to being delivered to your inbox. If a message successfully navigates every stage of filters, it gets placed into a delivery queue, and is sent along to your mail server immediately.

Each stage of filters assigns a score to the incoming message, and based upon the user's filter sensitivity (set in the control panel at the individual or domain level), the cumulative score of the message determines the action that the system takes for that message.

Messages get placed into one of three buckets: "definitely spam", messages that the system has identified as absolutely a spam message, "possibly spam", messages that the system thinks might be spam but isn't absolutely sure, and "clean", messages that the system thinks aren't spam.


Comprehensive feature set

Everything that makes up the Heluna service for your email.


  • Reputation filter

    Catch senders with bad or unknown reputations online

  • DNSBL filters

    Block hundreds of thousands of spammers by IP address

  • Honeypot filter

    Find brand new spam originators sending to invalid addresses

  • SPF filter

    Ensure messages are only allowed to originate from accepted servers

  • Recipient call-ahead

    Prevent dictionary attacks on your infrastructure

  • Bayesian network

    Machine learning for spam messages, high confidence spam filtering

  • URIBL filters

    Catch messages that have spam URLs embedded in them

  • Content filters

    Filter out messages based on headers or body content


  • Sensitivity

    Adjust the score a message needs to get to be quarantined or delivered

  • Reporting

    View current message logs and statistics for users or domains

  • Quarantine digest

    Daily or weekly emails with the contents of user or domain quarantines

  • Approved senders (whitelist)

    Senders marked as possibly spam can be overridden and set to clean

  • Blocked senders (blacklist)

    Block messages from senders who you never want to see

  • Quarantine view, resend

    View or immediately resend a message from your quarantine to your inbox

Additional Notes

Preferences, logs, statistics, and quarantine run at the individual mailbox or the domain-wide level. Individual mailboxes inherit the domain preferences if a Heluna login isn't set up for that mailbox.

View statistics, invoices, individual user actions, logins, and more at the account level.

Set up individual logins with distinct roles: either a regular user mailbox, a domain-wide admin to manage a specific domain, or an account admin to manage all domains under your account. Logins can enable two-factor authentication for additional user security.

New clients are encouraged to let the Heluna system run with minimal customization and preferences for a while; if your users are logging into a website to constantly review quarantines, add approved senders, and so on, you aren't reducing the cost of spam at all. Heluna strives to be completely hands-off, and we encourage our users to treat us as an invisible layer of filtering.

End-to-end security

Heluna provides a safe environment for the transit of your email.


Heluna provides opportunistic TLS encryption for all incoming and delivered messages, and only allows TLS/SSL access to the client dashboard. We don't keep any copies of clean messages that have been delivered to your domain. When you use Heluna, you can rest assured that your email is secure.

The Heluna website also uses optional two-factor authentication to secure your account. You can browse your message log, set your preferences, and see your statistics all while knowing that only you can see your information.

Reactive architecture

Heluna was created from the ground up to handle your messages.

We've engineered the overall system architecture to be reactive under load. Using Amazon's AWS, Heluna can scale to meet incoming message demand very efficiently. Even under heavy loads, Heluna provides comprehensive message filtering for all of your email.

With modern architecture and operations setup, the Heluna service is built to be extremely resilient to component failure. Thanks to the nature of SMTP we make sure that you're never losing messages even when your mail server goes offline.


Take all of these features out for a test drive.