[Mimedefang] greylisting does it still work?

[Jonas Eckerman]

 > But only once.  After that, if the zombie IP hits you again,
 > it's in your database and doesn't get stopped at _relay.

Yup. But a big amount of zombies never tried again at the time I 
implemented this.

>> This is done because some braindead mail servers doesn't (or 
>> didn't) understand tempfails as answers to RCPT.

> My response to that is to ignore it,

Unfortunately, that response has not been ok here. People complained.

 > since so many large places (Yahoo,
 > Verizon, Comcast) will tempfail after RCPT for various
 > reasons...probably not greylisting, though.  If you can't send 
mail to
 > any of those places, you'll fix the problem pretty quick.

You might think so... But that wasn't what was happening when I 
implemented our greylisting.

The situation might well have changed now though.


> Since you already have a database for greylisting, why not put the 
> valid recipients there, too?  Use a cron job to update it on whatever 
> basis makes sense.

While that is a good idea in many systems, it'd be kind of a hard 
job here. I do cache the recipient checks in the database though.

One of the systems is a BBS/news-server/mail-list-host combo with 
  between 200 and 300 newsgroups (all groups can be accessed as 
mailllists), with multiple aliases for some groups, and removes 
some stuff from the end of list names/aliases (-r, -l, -request 
and that kind of things).

Since only addresses subscribed to a list can send mail to it, a 
recipient can be valid for one sender while beeing invalid for 
another, just storing all aliases etc won't be enough either...

Another system also has a maillist manager (but not the same 
software), and about 50 lists.

The system that's not on our LAN only has no lists or such, but I 
have no control of that system and I don't know what addresses 
are valid there.

Regards
/Jonas

-- 
Jonas Eckerman, FSDB & Fruktträdet
http://whatever.frukt.org/
http://www.fsdb.org/
http://www.frukt.org/