# chenjj/espoofer

An email spoofing testing tool that aims to bypass SPF/DKIM/DMARC and forge DKIM signatures.🍻

Repository: https://github.com/chenjj/espoofer
Canonical: https://ross.abutalabs.com/products/espoofer
Homepage: https://www.jianjunchen.com/p/composition-kills.USESEC20.pdf
Language: Python
License: MIT
License Family: permissive
Topics: spoofing-emails, spf, dkim, dmarc, smtp, phishing-attacks, email-spoof, phishing, spoofing, dmarc-bypass, hacking, penetration-testing, security, security-tools
Last push: 2022-05-13T06:52:47+00:00

## Health v2 (maintenance only)
Score: 32/100 (v2, computed 2026-09-02T17:46:02.011165+00:00)
- activity 0, release rhythm 35, longevity 100
- inputs: {"age_days": 2628, "days_push": 1573, "days_rel": null, "gap_med": null, "n_releases_24m": 0}
- flags: no_releases
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 1745, forks 281 (observed 2026-08-28T04:05:30.604323+00:00)

## What it is
espoofer is a Python-based testing tool that crafts spoofed emails to bypass SPF, DKIM, and DMARC authentication, including forged DKIM signatures. It packages research-identified attack cases to help mail server administrators and penetration testers assess whether email servers and clients are vulnerable to sender spoofing.

## Use cases
- test whether my mail server is vulnerable to SPF/DKIM/DMARC bypass attacks
- check if email clients can be tricked by spoofed sender addresses
- run email sender spoofing test cases during a penetration test
- verify DKIM signature forgery against a target email system
- audit email authentication configuration after deploying SPF and DMARC
- reproduce email sender spoofing research attacks from the USENIX 2020 paper

## When to choose
- you administer a mail server and want to validate your SPF/DKIM/DMARC defenses
- you are a security practitioner testing email spoofing exposure of an organization
- you need a ready-made suite of known email authentication bypass test cases

## When to avoid
- you want to send legitimate bulk or transactional email
- you need a general-purpose email sending library or SMTP client
- you lack authorization to test the target email system

## Facets
- artifact type: cli-tool
- maturity: maintenance
- function: penetration-testing, security, email, testing
- domain: security, penetration-testing, email
- platform: python, cli, cross-platform
- tags: email-spoofing, spf, dkim, dmarc, smtp, phishing-testing, security-audit

## Member repositories
- chenjj/espoofer (main) score 32

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:05:30.604323+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-30T03:29:13.636481+00:00, confidence not recorded.
  - readme: https://github.com/chenjj/espoofer (fetched 2026-08-28T04:05:30.604323+00:00, sha 3d3f92566c0d)
  - registry_pypi: https://pypi.org/pypi/espoofer/json (fetched 2026-08-29T11:07:08.495738+00:00, sha b2e004ed9b4c)
- Data as of 2026-08-30T08:39:29.467469+00:00.