With this module one can validate DKIM Signatures in mails and also create DKIM
signatures for mails.

The main difference to Mail::DKIM is that the validation can be done
iterative, that is the mail can be streamed into the object and if DNS lookups
are necessary their results can be added to the DKIM object asynchronously.
There are no blocking operation or waiting for input, everything is directly
driven by the user/application feeding the DKIM object with data.

This module implements only DKIM according to RFC 6376.
It does not support the historic DomainKeys standard (RFC 4870).