[Mimedefang] Starting all over to kill invalid users

[Steve Campbell]

I had a thread before about using MD with MailScanner. The thread was about 
whether I should use MD on a machine with MS to block invalid users from a 
secondary MX to the mail store where the real mailboxes lived. That thread 
sort of ended with me learning a whole lot about the email process, but I 
didn't end up with much useful output on my end.

Now I see the thread about the "md_check_against_smtp_server" function. I 
installed MD (for the first time), set up sendmail, modified the subroutine 
"filter_recipients" to handle 3 domains, changed the sysconfig/mimedefang 
file, and after correcting my typos, I find it works!

I did get a few questions about the process, though, that may be answered if 
any of you have the time.

1).   How much of mimedefang-filter would be needed if all's I wanted to do 
was do this look-ahead check? I really haven't determined if filter-begin, 
filter, etc is needed if I start mimedefang with the -t flag to do these 
checks.

2).   It would be nice to be able to do the md_check_against_smtp_server 
using an IP address as opposed to a hostname for the variable $rcpt_host. 
Looking at my logs, I see where it checks the IP defined by my DNS for the 
$rcpt_host, even though I have a different internal address defined in my 
host file (much like sendmail does if you don't put square brackets around 
the IP), so I guess it is working correctly. Is there anyway to force the 
function to use an alternately-defined IP for a hostname?

Thanks so much for the great software and any help any of you might provide.


Steve Campbell
campbell at cnpapers.com
Charleston Newspapers