[GNC] Addition of Mailing List Subject Prefix

[Adonay Felipe Nogueira]

2018-04-10T21:44:15-0400 William Bixby wrote:
> Interesting, in my emails from Gnucash I do not see any headers with tags
> mailing-list
> mailed-by

Depends on email reader software (or webmail if you use it), although
good webmail also let's you inspect the message in raw form (which will
of course show all header fields).

> On most of them I see a tag
> List-id
> But that is not a field I can filter on from my ISP
>
> In this message from Dave I see my email as the to: and
> Gnucash Users <gnucash-user at gnucash.org  as the CC: but there is no List-id

Note that since you don't see "List-id" it means that the email message
came directly to the server of the email service provider you rely on
--- that means it didn't pass over the mailing list at the time the
message came to you ---, you should by now also have received a
duplicated message that comes from the mailing list bouncer and which
has the "List-id" header field.

> So the filters Dave suggests would be incomplete, a CC is also needed.
> Maybe also a 'From' just to be sure?
>
> The emails from the list seem to have a variety of header forms,
> perhaps depending on the mailers used for the reply, or the reply-to
> or reply-list or reply-all forms. Seems hard to keep track of all the
> possibilities.
>
> Instead of requiring 2-3 or more filters for each list, the subject
> code allows a single filter to do the job, consistently, never misses.

Some filters allow you to match field names with a regular expression
standard/syntax --- /e.g./: "^\(To\|Cc\|List-id\)" if they have
separated space to match only the field *names*, or
"^\(To\|Cc\|List-id\):.*gnucash-user at gnucash\.org" if they don't, both
examples use GNU Emacs regular expressions but the email filter you use
might require other syntax --- or the filter might also allow you to
chain some condition checks --- /e.g./: ( To OR Cc OR List-id ) ==
"gnucash-user at gnucash.org".