On Fri, May 22, 2020 at 04:17:24PM +0100, antlists wrote:
> If I understand what you are attempting correctly (not a given!) then what
> you are trying won't work. You're confusing multiple *folders* with multiple
> *users*.

Sorry, my original e-mail was quite nondescript.  Consider that  I  have  a  few
folders in my INBOX  maildir,  created  with  maildirmake(1)  -f:  Sent,  Trash,
Drafts, AcademicMatters, etc.

Should  an  e-mail  be  sent  to  ash+AcademicMatters@suugaku.co.uk,  it  should
automatically  be  redirected  into  the  appropriate   sub-maildir.    As   the
AcademicMatters folder is a folder inside the `ash` maildir,  there  is  only  a
single user involved, with multiple folders.

> This is, I believe, an RFC so Courier is simply implementing the spec.
> That's probably why there is precious little Courier reference material, it
> assumes you have the RFC to hand ...

It seems like sub-addressing  is  defined  in  #5233  [1].   Further  discussion
specific to the Sieve language is found in #5228 [2].  It seems like, to use the
example in [1], an e-mail addressed to `ken+sieve@example.org` is  sent  to  the
mailbox `sieve` belonging to `ken`.  In my case, this would be sending  mail  to
the `AcademicMatters` mailbox owned by `ash`.

> I don't know what happens with your "-" example, but it just looks wrong to
> me.

In my original message, I complained that the server was throwing out  an  error
stating that the corresponding entry could not be found  in  the  virtual  users
table.  It seems like the `recipient_delimiter` attribute in  Postfix's  main.cf
can specify an arbitrary delimiter, so  a  plus,  hyphen,  or  any  other  legal
character can be used to denote the sub-address.

With `recipient_delimiter = +`, e-mail sent to ash+*@suugaku.co.uk now  ends  up
in my inbox.  To inspect the text after the delimiter and move it to the correct
folder accordingly is a job for Courier's `maildrop`, I suspect.

> It should be looking for an AcademicMatters POP account, and then
> delivering the mail to a user account called ash on the server called
> AcademicMatters.

I don't really understand this sentence, sorry.  How can a user  account  called
`ash` also be called `AcademicMatters` ?  `AcademicMatters`  is  a  subdirectory
inside the `ash` user's inbox.

On Fri, May 22, 2020 at 08:52:23AM -0400, james wrote:
> Yes, but with mail-client/Thunderbird. The tricks (with thunderbird) are
> mostly related to how you set up your filters, and the order of the filters.

I would rather do this on the  server,  as  I  access  my  e-mail  from  various
machines, many of which are not listening for mail constantly.  I  also  dislike
Thunderbird as I find it too heavy for a mail client; (Neo)Mutt  has  served  me
well for a long time.

> Do post your findings, as I'm sure others would appreciate a robust (gentoo)
> solution, particularly if the feature list supports cell phones (android
> and/or apple cell phones) and those text/emails.

I think the problem you're posing is a very different one to  mine:  I  am  only
concerned with filtering e-mail to particular folders based on  the  address  to
which the mail was sent.  Your problem seems to  be  far  more  generalised  and
large-scale.

[1] https://tools.ietf.org/html/rfc5233
[2] https://tools.ietf.org/html/rfc5228

-- 

Ashley Dixon
suugaku.co.uk

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