Mar Matthias Darin wrote
> Here is what I use for this problem:
>
> acl_check_data:
> deny condition = ${if or
{{!def:h_Date:}{!def:h_Subject:}{!def:h_To:}}{yes}{no}}
> message = Message does not conform to RFC2822 standard
RFC 2822 says "The only required header fields are the origination date field and the originator address field(s). All other header fields are syntactically optional.", i.e. Date: and from: so your error message seems to be wrong. RFC 2822 does not require a Subject: or To: field as far as far as I can see.
Neil Youngman