authheaders

0.16.3 verified Fri May 01 auth: no python

A library wrapping email authentication header verification and generation, supporting DKIM, SPF, and DMARC. Current version 0.16.3, release cadence irregular with updates every few months.

pip install authheaders

Common errors

error AttributeError: module 'authheaders' has no attribute 'authentic_headers' ↓

cause Wrong import path; trying to import from wrong module.

fix

Use: from authheaders import authentic_headers

error ModuleNotFoundError: No module named 'authres' ↓

cause Missing dependency 'authres' (authentication-results package).

fix

pip install authres

error AttributeError: module 'authheaders' has no attribute 'dkim' ↓

cause The function 'dkim' is not directly exposed; you must import the submodule correctly.

fix

Use: from authheaders import dkim

error TypeError: authentic_headers() missing 1 required positional argument: 'mfrom' ↓

cause Incorrect call signature; 'mfrom' parameter required for DKIM/SPF.

fix

Provide all required arguments: authentic_headers(headers, ip, mfrom, helo=None, ...)

Warnings

deprecated The 'publicsuffix' package is deprecated; use 'publicsuffix2' instead. authheaders switched in 0.13.0. ↓

fix pip install publicsuffix2 and ensure authheaders >=0.13.0

breaking Removed 'importlib_resources' dependency in 0.16.1; now uses 'importlib.resources' (Python 3.9+). May break on Python 3.7/3.8. ↓

fix Use Python >=3.9 or pin to authheaders==0.16.0

gotcha The 'authentic_headers' function expects headers as a dict with case-insensitive keys. Providing 'From' instead of 'from' can cause silent failures. ↓

fix Ensure header keys are lowercase (e.g., 'from', 'to', 'subject')

gotcha The library may raise 'authheaders.errors.AuthError' for various failures; catch it explicitly. ↓

fix from authheaders.errors import AuthError

Imports

authentic_headers

wrong

from authheaders.authheaders import authentic_headers

correct

from authheaders import authentic_headers

The old deep import path is no longer correct.

dkim
wrong
```
import authheaders.dkim
```
correct
```
from authheaders import dkim
```
Common mistake: trying to import submodule directly.
spf
wrong
```
import authheaders.spf
```
correct
```
from authheaders import spf
```
Should import the function, not the submodule.

Quickstart

Generates Authentication-Results headers for a message. Requires dict of email headers and connecting IP.

from authheaders import authentic_headers

# Generate authentication-results header for a single email
headers = {'from': 'sender@example.com', 'to': 'recipient@example.com', 'subject': 'Test'}
result = authentic_headers(headers, '127.0.0.1', 'example.com', spf_timeout=5, dkim_timeout=5, dmarc_timeout=5)
print(result)