"Patch" as requested: possibly postfix-specific.
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^\w{3} [ :[:digit:]]{11} [._[:alnum:]-]+ dkim-filter\[[[:digit:]]+\]: [[:xdigit:]]{10} SSL error:04077068:rsa routines:RSA_verify:bad signature
^\w{3} [ :[:digit:]]{11} [._[:alnum:]-]+ dkim-filter\[[[:digit:]]+\]: [[:xdigit:]]{10}: bad signature data