RequiredHeaders gives no useful SMTP response

[ghen2]

Hi

I'd like to enable RequiredHeaders, but I noticed it provides no useful SMTP response, just a plain "550 5.7.1 Command rejected" (a Postfix default value?)

However the logs do contains a useful explanation like "RFC5322 requirement error: not exactly one Date field" or "RFC5322 requirement error: missing From field". Would it be possible to return this information in the SMTP response as well, so the client has an indication why his message got rejected? (as it is expected to reject some legit e-mail as well)