happyDeliver

An open-source email deliverability testing platform that analyzes test emails and provides detailed deliverability reports with scoring.

Features

• Complete Email Analysis: Analyzes SPF, DKIM, DMARC, SpamAssassin scores, DNS records, blacklist status, content quality, and more
• REST API: Full-featured API for creating tests and retrieving reports
• Email Receiver: MDA (Mail Delivery Agent) mode for processing incoming test emails
• Scoring System: 0-10 scoring with weighted factors across authentication, spam, blacklists, content, and headers
• Database Storage: SQLite or PostgreSQL support
• Configurable: via environment or config file for all settings

Quick Start

1. Build

go generate
go build -o happyDeliver ./cmd/happyDeliver

2. Run the API Server

./happyDeliver server

The server will start on http://localhost:8080 by default.

3. Integrate with your existing e-mail setup

It is expected your setup annotate the email with eg. opendkim, spamassassin, ... happyDeliver will not perform thoses checks, it relies instead on standard software to have real world annotations.

Choose one of the following way to integrate happyDeliver in your existing setup:

Postfix Transport rule

You'll obtains the best results with a custom transport tule.

1. Append the following lines at the end of your master.cf file:

+
+# happyDeliver analyzer - receives emails matching transport_maps
+happydeliver unix -     n       n       -       -       pipe
+  flags=DRXhu user=happydeliver argv=/path/to/happyDeliver analyze -recipient ${recipient}

2. Create the file /etc/postfix/transport_happyDeliver with the following content:

# Transport map - route test emails to happyDeliver analyzer
# Pattern: test-<uuid>@yourdomain.com -> happydeliver pipe

/^test-[a-f0-9-]+@yourdomain\.com$/  happydeliver:

3. Append the created file to transport_maps in your main.cf:

-transport_maps = texthash:/etc/postfix/transport
+transport_maps = texthash:/etc/postfix/transport, pcre:/etc/postfix/transport_maps

If your transport_maps option is not set, just append this line:

transport_maps = pcre:/etc/postfix/transport_maps

Note: to use the pcre: type, you need to have postfix-pcre installed.

Postfix Aliases

You can dedicate an alias to the tool using your recipient_delimiter (most likely +).

Add the following line in your /etc/postfix/aliases:

+test: "|/path/to/happyDeliver analyze"

Note that the recipient address has to be present in header.

4. Create a Test

curl -X POST http://localhost:8080/api/test

Response:

{
  "id": "550e8400-e29b-41d4-a716-446655440000",
  "email": "test-550e8400@localhost",
  "status": "pending",
  "message": "Send your test email to the address above"
}

5. Send Test Email

Send a test email to the address provided (you'll need to configure your MTA to route emails to the analyzer - see MTA Integration below).

6. Get Report

curl http://localhost:8080/api/report/550e8400-e29b-41d4-a716-446655440000

API Endpoints

Endpoint	Method	Description
/api/test	POST	Create a new deliverability test
/api/test/{id}	GET	Get test metadata and status
/api/report/{id}	GET	Get detailed analysis report
/api/report/{id}/raw	GET	Get raw annotated email
/api/status	GET	Service health and status

Email Analyzer (MDA Mode)

To process an email from an MTA pipe:

cat email.eml | ./happyDeliver analyze

Or specify recipient explicitly:

cat email.eml | ./happyDeliver analyze -recipient test-uuid@yourdomain.com

Scoring System

The deliverability score is calculated from 0 to 10 based on:

• Authentication (3 pts): SPF, DKIM, DMARC validation
• Spam (2 pts): SpamAssassin score
• Blacklist (2 pts): RBL/DNSBL checks
• Content (2 pts): HTML quality, links, images, unsubscribe
• Headers (1 pt): Required headers, MIME structure

Ratings:

• 9-10: Excellent
• 7-8.9: Good
• 5-6.9: Fair
• 3-4.9: Poor
• 0-2.9: Critical

Funding

This project is funded through NGI Zero Core, a fund established by NLnet with financial support from the European Commission's Next Generation Internet program. Learn more at the NLnet project page.

License

GNU Affero General Public License v3.0 or later (AGPL-3.0-or-later)