안녕 하세요?
버전 3.5까지는 필터링에 걸린 경우 리턴 문구가 모두 동일합니다.
따라서 필터 파일을 살펴보셔야 알수있습니다.
버전 3.6부터는 필터 파일을 DB로 변경 하면서 문구에 대한 필터링은 DB의 몇번째 문구 때문에 필터되었는지 리턴 메일에 포함 시켜줍니다.

가락동임 님이 쓴 글입니다.
--------------------------------------------------------------------
: > ----- Original Message -----
: > From: "Mail Administrator"
: > To:
: > Sent: Monday, October 31, 2005 2:01 PM
: > Subject: Mail System Error - Returned Mail
: >
: >
: > > This Message was undeliverable due to the following reason:
: > >
: > > Your message was not delivered because the destination computer refused
: > > to accept it (the error message is reproduced below). This type of
:error
: > > is usually due to a mis-configured account or mail delivery system on
:the
: > > destination computer; however, it could be caused by your message since
: > > some mail systems refuse messages with invalid header information, or if
: > > they are too large.
: > >
: > > Your message was rejected by mail.kjpretech.com for the following
:reason:
: > > Mail is reject ( filtering reject )
: > >
: > > Please reply to ****@****
: > > if you feel this message to be in error.
: > >
: >