The mailing list for listmasters using Sympa

["Stefan Hornburg (Racke)" <address@concealed>]

On 06/26/2017 05:46 PM, François Poulain wrote:
> Hi,
> 
> On our wwsympa we are getting numerous web requests like
> POST /wws/subscribe/listname
> from numerous output servers, with numerous emails to be subscribed.
> 
> Since we use auth scenario, confirmation email are sent to the
> recipients posted.
> 
> Each days we send hundreds emails which are blocked by Google (error
> 450-4.2.1 The user you are trying to contact is receiving mail at a
> rate that 450-4.2.1 prevents additional messages from being delivered).
> 
> There is no evidence regarding host/ip_addr or email addr which allow
> to easily thrash theses subscribe requests.
> 
> How do you mitigate with this? Is there a way to add tokens in the
> webforms in order to prevent (or at least increase cost of) this
> kind of massive spam?
> 
> Best regards.
> François
> 

Hello François,

one possible way would be to add a CAPTCHA to this subscribe form,
e.g. we are using reCAPTCHA on a couple of web sites.

Regards
        Racke

-- 
Ecommerce and Linux consulting + Perl and web application programming.
Debian and Sympa administration.