[Mailman-Developers] one-click unsubscribe

[Barry Warsaw]

On Wed, 2004-01-28 at 19:01, Jim Gottlieb wrote:
> Is anyone working on extending VERP-like features to allow for true
> one-click unsubscribe?

When you say "VERP-like" I think you mean more along the lines of a
mail-merge or content personalization feature.  I try to use the term
"VERP" to mean header, and particularly envelope sender techniques.

> Right now, it's at least three-click, plus waiting for the confirmation
> to arrive.  We'd really like to include a link in each message that
> will allow them to very easily get off our list.

You have to do this in an unguessable way, otherwise, attackers can
simply unsubscribe anybody they want from a mailing list.

> On a related note, if we were to send HTML email (I know, I know), will
> variables be expanded in the text we submit so that we could create
> links that will be different for each user?  So that, say with the
> current capabilities, we could have something like
> 
> <A HREF=http://mailman.nccom.com/mailman/options/kxt/%(member-address)s>Click
> here to manage your subscription</A>

Not in Mailman 2.1.  I know how to do this, and have proof-of-concept
code working for Mailman 3.  It requires Python 2.3 features, and will
look something like this:

http://lists.example.com/mailman/unsub/${mm:unsub_token}

I believe I have a way to limit, based on list configuration, such
"$mm:" substitutions to the headers and footers, or to allow such
substitutions to occur anywhere in the message text (headers, body, and
MIME attachments included).  Such substitutions would run at about the
speed of Python's string interpolation operator (read: much faster than
what Mailman 2.1 does).

-Barry