[Mailman-Developers] Approach for plugin ideas

[Aanand Shekhar Roy]

Based on the discussion with @Abhilash, Below is the modified   approach
for plugin ideas:

*Banned Words*:

>> 1. We create a common set of words that are to be banned in a mail.
>
> How do you create such a list, who decides which words are banned?

> Would it be possible to add/remove words from these lists from postorius?

We create a default list of such words, like common racial and abusive
words, the list will be displayed on the UI along with which we will
provide two buttons "add" or "remove" which can allow list admin to modify
it.

> Will this list be list specific or global to one mailman installation?

By default this list will be global to one mailman installation.But then,
it can be modified as per needs of the list admin so it will be specific
in general.

>> 2. In list settings we create an option for list admin to choose action
>>taken if a mail has banned words.
> What according to you should be sane default for this?
> Is is possible that
> the banned words be removed or replaced with ****** and the mail be sent
>to
> the list so as to ease the life of list-admins?
>

Yes it is possible in the pipeline of handlers where we can extract and
modify message string object, so the sane default will be replacing the
banned word with "****". But the UI will provide
options to list admin to change the default to "accept" or "discard".

>> 3. We need to create a new rule in src/mailman/rules that checks
>> for banned words in a msg string.
>> 4. This rule is to be implemented in
>> src/mailman/chains/builtin.py
>> where it takes the action as chosen by list admin and then the control is
>> passed further depending on the action taken.

*Confidential Information Check*:

>> 1. We need to create another rule which check for confidential info. like
>> phone no and address credit card no. using regexp search.
> How do you do that check? How can you differentiate any number from
>phone number,

Below is a regex for a 7 or 10 digit number, with extensions allowed,
delimiters are spaces, dashes, or periods :
For example: For numbers like (123) 456 7899, this helps in catching the
ones with an area code in parentheses ([0-9]\{3\})[ .-][0-9]\{3\}[
.-][0-9]\{4\}
We can extend it further to accommodate other international phone-numbers
as well.

>  or credit card number? (Using reg-ex, yes, but what would the rules
>be?)

For credit-card numbers like:

Visa : ^4[0-9]{12}(?:[0-9]{3})?$ All Visa card numbers start with a 4. New
cards have 16 digits. Old cards have 13.

MasterCard: ^5[1-5][0-9]{14}$ All MasterCard numbers start with the
numbers 51 through 55. All have 16 digits.

> Why is address a confidential information

It depends, for some lists it could be a confidential information.

>and how do you actually decide what
> level of confidentiality you want to maintain? Will that be
> configurable per-list or
> globally in a mailman installation?

We can provide provide checkboxes in postorius which will allow list admin
to mark  on the required fields.
Like 1,Phone number
      2,Credit-card No.
      3,Address, etc.

>> 2. If found we hold that message, and then we send an auto-reply to
>>sender
>> asking for confirmation if he
>> intends to post such information.
>> 3. This system works similar to the mail-back verification procedure
>>during confirmation of email while subscribing where potential
>> subscriber's reply decides the further action to be taken.
>
> How will you parse the response of the sender, will there be a
> pre-defined format
> like email commands in mailman?
Yes, we will have some commands like say "OK-forward" in reply that will
let it proceed further and "No-discard" if we don't want to.
>Will you provide option in postorius too for the
> same? If yes, how?

No, keeping same settings will remove the flexibility, sometimes I would
like to provide my phone number and sometimes no, so email command would
be a better option.

>> 4.Based on the user's response the held message will be processed
>>further.
>
> Where will the message be stored while mailman waits for the reply from
>the sender?

We will have to make a queue similar to held message queue for this purpose.

> Will there be a timeout for response after which the email will
> automatically be
> rejected (or discarded? )
> or will mailman wait forever for the
> response? If you plan
> to timeout what would be default value?

The timeout will be there for a week after which it will be discarded.

>> TIMED VACATION:

First, I will try to implement above two ideas and if the time frame will
allow then I would proceed on this further, otherwise I would like to make
this one after Gsoc period.