strange word

[Jack Raats]

>From my logfile

Out: 554 5.7.1 Service unavailable; Sender address
     [obviouslya...@mypricepilot.com] blocked using bogusmx.rfc-ignorant.org;
     Domain has demonstrably bogus MX records

Is this error (demonstrably)  made by postfix or rfc-ignorant?

Jack