Fruneau/pfixtools — pull request #10 by driskell (2014-02-28 20:17:26+00:00)
Title: 400 is error - should be returning 500 which is not found

Looks like I got the code wrong there - it should be 500 to mean NOT FOUND. Otherwise with -I option it throws back 400 and postfix delays delivery thinking its a failure.

http://www.postfix.org/tcp_table.5.html
Has the codes.