smtpdummy: Support SMTPUTF8

config/scripts/smtpdummy

@@ -56,6 +56,7 @@ if __name__ == "__main__":
         env_var="SUBJECT",
         default=f"Test message {now.strftime('%H:%M:%S')}",
     )
+    parser.add_argument("-8", "--smtputf8", env_var="SMTPUTF8", action="store_true")
     parser.add_argument("-c", "--callout", env_var="CALLOUT", action="store_true")
 
     parser.add_argument("-b", "--body", env_var="BODY", default="")
@@ -193,7 +194,7 @@ Input arguments:
             + password.encode()
         ).decode()
         send(f"AUTH PLAIN {encoded}")
-    send(f"MAIL FROM: <{args.sender}>")
+    send(f"MAIL FROM: <{args.sender}>" + (" SMTPUTF8" if args.smtputf8 else ""))
     for receiver in args.receiver:
         send(f"RCPT TO: <{receiver}>")
     if not args.callout: