Donald Brooks wrote:
> I have one particular domain on my mail server that gets a LOT of brute
> force address harvesting attmepts. Over time, I noticed that most of the
> usernames are repeated over time, usually withing a few days.
> 
> I've come up with what I think is a decent defense against it, so I
> thought I would share, and would like some input if there may be a
> better way, or any improvements to be made. Here's what I've done:
> 
> Take a complete 7 day maillog file, and use grep to extract all the
> lines containing 'invalid address rejected:"
> 
> Using Excel I made colums separated at the : and the @ which gives me
> one column with only the user names of the offending addresses.
> 
> You could use the uniq command, to filter out duplicate entries,
> although I haven't for this initial test.
> 
> I dumped all this to a text file called invalid.txt in my assp
> directory.
> 
> I then changed the Penalty Trap Address (spamtrapaddresses) value to
> file:invalid.txt

I wrote that automates that some time ago.
http://scripts.asspsmtp.org/invalidAddresses2PenaltyTrap.zip

Just change the paths and set the minCount to what you want and you 
should be good to go.

> Perhaps something similar could be incorporated into future releases?

Probably not.

Kevin

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