Add email.eml

[fynnkroeger]

This is the smalles possible Email that is completely valid according to RFC5322. It does not use obsolete syntax that MUST NOT be sent but MUST be able to be parsed according to RFC5322. The body of this message ist empty.
According to https://pretty-rfc.herokuapp.com/RFC5322#fielddefs we only need the orig-date and from header-fields to be present, the rest is optional. By following the ABNF for these we get:

orig-date
"Date:" date-time CRLF
"Date:" [ day-of-week "," ] date time [CFWS] CRLF
"Date:" date time CRLF
"Date:" day month year time CRLF
"Date:" ([FWS] 1*2DIGIT FWS) month year time CRLF
"Date:" (1*2DIGIT FWS) month year time CRLF
"Date:" ("1" " ") month year time CRLF
"Date:" "1 " month year time CRLF
"Date:1 " month year time CRLF
"Date:1 " "Aug" year time CRLF
"Date:1 Aug" year time CRLF
"Date:1 Aug" (FWS 4*DIGIT FWS) time CRLF
"Date:1 Aug" (" " "1900" " ") time CRLF
"Date:1 Aug" " 1900 " time CRLF
"Date:1 Aug 1900 " time CRLF
"Date:1 Aug 1900 " time-of-day zone CRLF
"Date:1 Aug 1900 " (hour ":" minute) zone CRLF
"Date:1 Aug 1900 " ("00" ":" minute) zone CRLF
"Date:1 Aug 1900 " ("00" ":" "00") zone CRLF
"Date:1 Aug 1900 " "00:00" zone CRLF
"Date:1 Aug 1900 00:00" zone CRLF
"Date:1 Aug 1900 00:00" (FWS ( "+" / "-" ) 4DIGIT) CRLF
"Date:1 Aug 1900 00:00" (" " "+" "0000") CRLF
"Date:1 Aug 1900 00:00" " +0000" CRLF
"Date:1 Aug 1900 00:00 +0000" CRLF

and

from
"From:" mailbox-list CRLF
"From:" (mailbox *("," mailbox)) CRLF
"From:" (mailbox) CRLF
"From:" (name-addr / addr-spec) CRLF
"From:" (addr-spec) CRLF
"From:" (local-part "@" domain) CRLF
"From:" ((dot-atom / quoted-string) "@" domain) CRLF
"From:" ((dot-atom) "@" domain) CRLF
"From:" (([CFWS] dot-atom-text [CFWS]) "@" domain) CRLF
"From:" ((dot-atom-text) "@" domain) CRLF
"From:" ((1*atext *("." 1*atext)) "@" domain) CRLF
"From:" ((1*atext) "@" domain) CRLF
"From:" ("a" "@" domain) CRLF
"From:" ("a" "@" (dot-atom / domain-literal)) CRLF
"From:" ("a" "@" (dot-atom / domain-literal)) CRLF
"From:" ("a" "@" dot-atom) CRLF  ; same as the other dot-atom
"From:" ("a" "@" "a") CRLF
"From:a@a" CRLF