+PDKIM >> raw hdr: {CR}{LF}
+PDKIM >> raw hdr: Message{SP}1{CR}{LF}
+PDKIM >> raw hdr: .{CR}{LF}
+PDKIM >> raw hdr: rset{CR}{LF}
+PDKIM >> raw hdr: mail{SP}from:<x@y>{CR}{LF}
+PDKIM >> raw hdr: rcpt{SP}to:<2@b>{CR}{LF}
+PDKIM >> raw hdr: data{CR}{LF}