Grey Trapping
Posted November 20, 2006 @ 11:34 am EST
By merdely in OpenBSD, Tech

emailTo cut down on SPAM, I’ve implemented GreyTrapping (or SpamTrapping) using OpenBSD’s spamd.

I’ve noticed a LOT of spammers attempting to send to email addresses that don’t exist on my domain:


Some of them (mikeform@erdelynet.com and ssh-l@erdelynet.com) were email addresses that I did use at one time, but now should only be sent to by web-scrapers.

There are two purposes of this page:

  1. To let legitimate senders who have incorrectly emailed an address above know why they’re being blocked.
  2. To publish the list of grey trapped addresses so that more web-scraping spammers will get caught.

So, what happens if an email gets sent to one of my grey trapped addresses? That sending server cannot send me any more email for 24 hours. After 24 hours, that server can send emails to my server again, but not to a grey trapped address or it’ll be another 24 hour blacklisting.

What happens if you get blacklisted because of this? Leave me a comment on this page. All comments are moderated and I’ll get a message from you. If I determine that you really shouldn’t have been grey trapped, I’ll remove your temporary blacklist entry. Unless this becomes a problem, then, wait 24 hours.


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