Spam filtering

EmailConnect provides built-in spam filtering powered by Rspamd to protect your webhooks from unwanted emails. For Pro users, spam analysis is automatically enabled on all custom domains.

How spam filtering works

Every email sent to your Pro custom domains is automatically analyzed by Rspamd, which:

  • Checks SPF, DKIM, and DMARC authentication
  • Analyzes email headers and content patterns
  • Checks sender reputation against blocklists
  • Identifies phishing attempts and malicious content
  • Assigns a spam score from 0 (ham) to 15+ (definite spam)

The spam score and analysis results are included in every webhook payload, giving you full visibility into email authenticity.

What's included in webhooks

When spam filtering is active, your webhook payload includes a spam object:

{
  "message": {
    "sender": { "email": "user@example.com" },
    "subject": "Hello world",
    ...
  },
  "spam": {
    "score": 2.3,
    "threshold": 5.0,
    "engine": "rspamd"
  }
}
Field Description
score The spam score (0 = clean, higher = more likely spam)
threshold Reference threshold (typically 5.0)
engine The spam detection engine used

Controlling spam behavior with alias rules

While spam analysis runs automatically, you decide what happens based on the results. Use alias rules to define actions based on spam score:

Example: Block high-scoring spam

Create a rule to reject emails with a spam score >= 7:

  1. Go to your alias settings
  2. Click "Configure rules"
  3. Add a condition: Spam score >= 7
  4. Set action: Block
  5. Optionally enable sender notification

Example: Tag suspicious emails

For moderate spam scores, you might want to deliver but tag:

  1. Add a condition: Spam score >= 5
  2. Set action: Tag
  3. Save the rule

Tagged emails are delivered with an X-EmailConnect-Tagged: spam header and X-EmailConnect-Spam-Score header, allowing your webhook endpoint to handle them differently.

Example: Allow trusted senders regardless of score

Combine spam score with sender rules:

  1. Condition 1: Sender domain equals @trusted-partner.com
  2. Set action: Allow

This ensures emails from trusted partners are never blocked, even if they trigger spam detection.

Understanding spam scores

Score range Interpretation Recommended action
0 - 2 Clean email Allow
2 - 5 Slightly suspicious Allow or monitor
5 - 7 Likely spam Tag or block
7 - 10 Very likely spam Block
10+ Definite spam Block

These are guidelines - adjust thresholds based on your use case.

Best practices

For public-facing addresses (support@, info@)

  • Set a rule to block spam score >= 7
  • Consider tagging scores >= 5 for manual review
  • Enable sender notifications for blocked emails

For transactional addresses (orders@, invoices@)

  • Be more conservative - block only score >= 10
  • Allow known sender domains explicitly
  • Monitor for false positives initially

For internal automation

  • Consider lower thresholds since automated emails can sometimes trigger spam detection
  • Use sender allowlists for known automation sources

Availability

Plan Spam filtering
Free Not available
Pro Automatic on all custom domains
Enterprise Automatic with custom configuration

System aliases (@user.emailconnect.eu) use basic processing and do not include spam analysis.

FAQ

Is spam filtering automatic for Pro users?

Yes. Once you have a Pro subscription, spam analysis runs on all emails to your custom domains. You don't need to enable anything.

Do I have to create rules?

No. Without rules, all emails are delivered to your webhook with spam data included. You can filter in your own application using the spam score, or set up rules in EmailConnect to block/tag before delivery.

What happens to blocked emails?

Blocked emails are rejected at delivery time. If you enable sender notification, the sender receives a bounce message explaining the rejection.

Can spam filtering block legitimate emails?

It's possible. If you suspect false positives:

  1. Check the spam score in your webhook logs
  2. Create an allow rule for the sender domain
  3. Lower your blocking threshold
  4. Contact support if issues persist

Does spam filtering affect email speed?

No. Spam analysis runs in real-time as part of email processing with negligible latency impact.

Can I see why an email was flagged?

The spam score indicates the overall suspiciousness. For detailed analysis (which rules triggered), contact support with the email details.

Related documentation