ISO RegExp example to block bot subscribe requests

Hello, List is running on Mailman version 2.1.20.
Last several days began receiving hundreds of bot subscription requests (all gmail addresses).
All of format like: blech+12345678@gmail.com zark+98765432@gmail.com etc.
I entered following regex lines in Privacy Options -> Subscription Rules -> ban_list
^.*blech ^.*zark etc
Temporarily did the job, but the bot adapted and changed the prefix of the address string to: crap+12345678@gmail.com grum+98765432@gmail.com etc.
Unable to keep up with the bots changing the address prefix.
Common to ALL of the bot subscribe requests is including the "+" symbol in the email address
So I tried entering RegExp ^.*+ but Mailman rejected this entry.
But was able to enter RegExp of ^.*/+ However that allowed all the bot spam requests through.
Can anyone recommend an example of a RegExp entry which would solve my dilemma?
Note: Unfortunately I do not have access to the server so unable to configure SUBSCRIBE_FORM_SECRET
Thanks for any ideas.

Woody Mon via Mailman-Users writes:
So I tried entering RegExp ^.*+ but Mailman rejected this entry.
That's illegal syntax for a regexp because "+" is an operator.
The version you want is "^.*\+". However, that is a very bad idea if you have any posters with email skills, because embedding "+" in the return address for outgoing mail is a common way to identify the source of incoming replies.
A more conservative regexp would be "^[a-z]+\+[0-9]+@" which will catch the pattern of LETTERS "+" DIGITS.

On 08/27/2015 08:32 PM, Stephen J. Turnbull wrote:
Also, see my reply to Nelson Kelly at <https://mail.python.org/pipermail/mailman-users/2015-August/079671.html>.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan

Woody Mon via Mailman-Users writes:
So I tried entering RegExp ^.*+ but Mailman rejected this entry.
That's illegal syntax for a regexp because "+" is an operator.
The version you want is "^.*\+". However, that is a very bad idea if you have any posters with email skills, because embedding "+" in the return address for outgoing mail is a common way to identify the source of incoming replies.
A more conservative regexp would be "^[a-z]+\+[0-9]+@" which will catch the pattern of LETTERS "+" DIGITS.

On 08/27/2015 08:32 PM, Stephen J. Turnbull wrote:
Also, see my reply to Nelson Kelly at <https://mail.python.org/pipermail/mailman-users/2015-August/079671.html>.
-- Mark Sapiro <mark@msapiro.net> The highway is for gamblers, San Francisco Bay Area, California better use your sense - B. Dylan
participants (3)
-
Mark Sapiro
-
Stephen J. Turnbull
-
Woody Mon