Computes a dkim signature for an email message
dkimproxy-sign [options] < original_email.txt options: --method=METHOD --selector=SELECTOR --debug-canonicalization=FILE
dkimproxy-sign --help to see a full description of the various options
--method Determines the desired canonicalization method. Possible values are simple, simple/simple, simple/relaxed, relaxed, relaxed/relaxed, relaxed/simple.
--debug-canonicalization Outputs the canonicalized message to the specified file, in addition to computing the DKIM signature. This is helpful for debugging canonicalization methods.