I find the most reliable way to filter mailing lists is on the List-id header.
It would be nice if this was an optional template that could be pre-filled from
a message.

(In reply to comment #0)
> I find the most reliable way to filter mailing lists is on the List-id header.
> It would be nice if this was an optional template that could be pre-filled from
> a message.
> 

You can achieve this by creating a custom template

1) Open quickFilters Settings  (right-click the quickFilters Assistant button)
2) click advanced
3) activate Custom Templates
4) click Create New...
5) Enter the name for the tmeplate (e.g. List-Id)
6) select List-IF on the condition and select List Id from the Custom Variables
(top right of the dialog) to fill in as value
7) save

Next time you create a filter a new template "List-Id" will be shown

I am reopening this bug now, maybe we can add this improvement for our standard
users. At tghe moment, the template "Mailing List" obviously describes
something else:

"Similar to Based on Sender, but it doesn't fill the 'to' condition field"

One possible modification would be to add the List-Id behavior in case a
non-empty list-id header can be found. In case no list-id field is found we
could still fall back to he old behavior. For collecting multiple emails in a
filter list the template "Group" can be used.

Apart from changing the behavior, the most work will be to explain this in the
description field. I think an additional (localised) explanation will be in
order.

Created an attachment (id=8592) [details]
3.8.2 pre 45

Prerelease version with template "Mailing List" using (and pre-filling from
email) new header condition of "list-id" - if list-id doesn't exist in the
email you're creating the filter from, it will use the sender address instead
(old behavior).

Description:

"Useful for mailing lists with 'List-Id' field. If this is not set it will use
the sender's address instead."