[Mimedefang] Need help with filter_relay

[Sevo Stille]

Mark Penkower wrote:

> Here, "dsl" is the flag
...
> 1 - It is my suspicion that bouncing emails with these keywords in the
> "from" header will only bounce spam.  Am I correct here?

Not at all. Even beyond the general political and technical issues with 
DUL filtering, a mere match on host names that contain strings typical 
for dialup lines will inevitably have even more false positives than DUL 
lists - you'd even catch those DSL leased line hosts lucky enough not to 
be on one netblock with dialups...

If you really want to reject dialups broadly, you'd better use a DUL 
list lookup. And you might want to consider whether MD/SA isn't overkill 
for you - if you don't use its features beyond the abilities of plain 
sendmail, you'd be wasting CPU and memory.

Sevo