[Mailman-Users] Spam Subscriptions

Phil Stracchino phils at caerllewys.net
Fri Feb 23 11:10:33 EST 2018

On 02/23/18 10:07, David Andrews wrote:
> Secondly, there is some commonality in the subscribe addresses, are 
> there strings I can use to discard the subscribes so I never have to see them.
> Below are examples, there is a common word, or a common word, a 
> period ., and another common word, then a plus sign + then a 4 5 or 6 
> character word, all alpha, and @gmail.com
> Here are examples:
> dragonommz+
> jwmidnight+
> nommz.naidoo+
> If I could knock these out, it would be helpful.  This has happened 
> several times previously, but has always stopped after a few weeks. 
> This time it has been a couple months.

You can't filter based on that address format.  (At least, not and be

This format, plus-extension, is a legitimate address structure
specifically for the purpose of generating traceable throwaway
addresses.  If I give you reddog+thislist at example.com as my email
address, which I receive at my address reddog at example.com, and I've
given that to no-one else, and a few weeks later I start getting random
spam sent to reddog+thislist at example.com, I know you have (intentionally
or otherwise) leaked my email address.

Just because an address is plus-extended does not mean it is spam.  If
you choose to refuse extended addresses, you risk refusing legitimate

Have you considered requiring CAPTCHAs for subscription?

  Phil Stracchino
  Babylon Communications
  phils at caerllewys.net
  phil at co.ordinate.org
  Landline: +1.603.293.8485
  Mobile:   +1.603.998.6958

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