Sendmail: How does one blacklist annoying spammers?

[Genes MailLists]

On 06/27/2010 09:47 PM, Tim wrote:
> On Sun, 2010-06-27 at 14:08 -0400, Genes MailLists wrote:
>>  So if you're gonna gray list - please whitelist all the standard ISP
>> outbound mx hosts ...
> 
> That's gotta be a huge list.  And won't some of them be spam sources,
> anyway?
> 

  Not huge at all - I'm doing this for the outbound MX's of trusted mail
senders.  Google uses about 2,700 outbound .. they are all readily
available. So we're talking a few thousand hosts.

 And not doing this only causes a 3 second delay anyway.

  Your question if gmail official hosts sends spam - even if it does,
the greet pause is not going to help in this case anyway - because gmail
servers follow the correct smtp protocols.

 Spammer machines often dont - they send out the mail and ignore all
protocols - that why greet pause is so effective.

  This splat-with-no wait is classic of spammers - e.g. a pc bot - they
program them to send the header, send the body. close. This kind of bot
will not get through the greet pause delay.


  gene