Re: [exim] Using + to specify delivery folders in addresses

On 2009-02-09 at 16:50 -0500, Eli Sand wrote:
> I've been toying with the idea of using the "+" character to denote a folder
> separator for local addresses, so that I could use addresses like
> eli+exim-users@??? and have email delivered to the eli@???
> account under the "exim-users" folder (if it existed).
>
> I'm wondering if people have this implemented, and if so how well it works
> (as in, does it get exploited regularly, or cause other problems or
> configuration issues/complexities), as well as wondering if anyone may
> provide configuration pieces showing how they've implemented this (as well
> as where it's implemented, such as in ACLs or routing - or both).

I pass through the +subaddress over LMTP to Cyrus IMAP; if a user's
folder 'foo' has the posting right granted to anyone, then folder foo
accepts the mail sent to user+foo, otherwise it goes into the main
INBOX.

Works for me, but then I am happy at the command-line and can speak IMAP
passably well. You need an IMAP client that understands ACLs to make
this viable, which in the GUI realm is probably only Mulberry.

The accepting Router needs:
local_part_suffix = +*
local_part_suffix_optional

Relevant alias redirects need to phrase "data =" carefully to preserve
the subaddress ($local_part_suffix).

The Transport (using the lmtp driver) needs "rcpt_include_affixes".

You need to not disable "anyoneuseracl" in Cyrus imapd.conf.

-Phil