Binary package “python3-authheaders” in ubuntu focal

Python 3 module for generating email authentication headers

 Authheaders can generate both authentication results header fields and DKIM/
 ARC sighatures. It can perform DKIM, SPF, and DMARC validation, and the
 results are packaged into a single Authentication-Results header. It can
 also DKIM and ARC sign messages and output the corresponding signature
 header fields.
 This is the Python 3 version of the package.