[Mailman-Users] ISO speciific RegExp to filter/discard bot subscribe requests

[Mark Sapiro]

On 08/27/2015 02:49 AM, Nelson Kelly wrote:

> 
> Common to ALL of the bot subscribe requests is including within the the
> email address a "+" symbol.
> 
> So I tried entering RegExp ^.*+ but Mailman rejected this entry.


Because '+' means 1 or more of the preceding, but the preceding is a
repeat itself so it's a bad regexp.

> But was able to enter RegExp of ^.*/+
> However that allowed all the bot spam requests through.


because that says 0 or more of anything followed by 1 or more slashes
(/) which is unlikely to match anything. (You probably wanted ^.*\+ but
see below.)


> Unable to keep up with the bots changing the address prefix.
> 
> Can anyone recommend an example of a RegExp entry which would
> prevent/solve this dilemma?


Yes.

^.*\+\d{3,}@

See
<https://mail.python.org/pipermail/mailman-users/2015-August/079668.html> for
a bit more.

-- 
Mark Sapiro <mark at msapiro.net>        The highway is for gamblers,
San Francisco Bay Area, California    better use your sense - B. Dylan