[Mimedefang] bounce check with sendmail and md_check_against

[Wayne]

Hello All,

I know everyone has probably figured this out but me. I am using 
md_check_against_smtp_server on my mimedefang server to check usernames 
before sending the mail to my server. I seem to have a lot of bounce 
messages that get sent from my server with invalid from addresses. I know 
there are some that are being rejected because of full mail boxes and I can 
understand those but I have messages that are being rejected by unknown user 
and then the bounce fails. These end up in my postmaster account. I have 
also notice that at times AOL or some other provider will black hole me for 
this. I don't know why these messages don't get rejected by 
md_check_against_smtp_server. How do I keep my server to discard these 
messages without trying to send them?

Thanks in Advance
Wayne