Sendmail: How does one blacklist annoying spammers?

Joel Rees joel.rees at
Mon Jun 28 07:36:31 UTC 2010

On Jun 26, 2010, at 10:36 AM, Tim wrote:

> On Fri, 2010-06-25 at 14:54 -0700, JD wrote:
>> I wonder how Google does it. only .01% of my google email is spam.
>> The spam folder contains tons of spam, and it is automatically purged
>> by google.
> When you're a large mail host you have one big advantage in spam
> killing:  You will receive tons of identical messages, many  
> addressed to
> bogus users, or honeypot addresses (addresses that you leak out,
> somehow, that aren't for real mail use).  When you receive large  
> numbers
> of identical messages, especially to non-real addresses, you know that
> they're spam, and you can mark every single one of them as being spam
> with 100% confidence.  You don't need to check for false positives, as
> no real mail will be sent to such addresses.  Whereas it is  
> possible for
> lots of users to receive identical mail, if you have lots of people
> subscribed to some popular lists.
> I've done that (honeypotting) in the past, and it's a reliable
> technique.  Unlike many other anti-spam techniques which falsely
> identify so many real messages as being spam that they make using  
> them a
> waste of time (if you're having to keep on checking your spam box,
> manually, there's no point in running anti-spam software).  Not to
> mention the problems caused when users have no idea that they must  
> check
> for false detections, and simply never see some of their mail.
> This is harder to do on an individual level, because most of your spam
> messages are different from each other.

At the individual level, I keep telling myself I'm going to set up a  
honeytrap, or maybe it should be called flypaper.

Deliberately leak trap addresses in places I tend to use my real  
addresses, auto-blacklist anything that hits the trap addresses.

Haven't got around to it yet.

> So you're left with trying to
> look for *similarities* to prior spam.  Though it is possible to make
> use of other people's honeypotting data (the various anti-spam lists
> that you've seen discussed in other messages in this thread).
> -- 
> [tim at localhost ~]$ uname -r
> Don't send private replies to my address, the mailbox is ignored.  I
> read messages from the public lists.
> -- 
> users mailing list
> users at
> To unsubscribe or change subscription options:
> Guidelines:

More information about the users mailing list