knowledge of salmon signatures. The salmon signature in this case MUST be the
exact string 'NOTSIGNED' to indicate that the author (From address) cannot be
validated using salmon verification. This message MUST be relayed by a Sender
knowledge of salmon signatures. The salmon signature in this case MUST be the
exact string 'NOTSIGNED' to indicate that the author (From address) cannot be
validated using salmon verification. This message MUST be relayed by a Sender