Re: [gentoo-user] Courier Sub-addressing

[antlists <antlists@youngman.org.uk>]

On 21/05/2020 21:14, Ashley Dixon wrote:
> Hello,
> 
> I am attempting to set up sub-addressing on my  Courier  mail  server,  allowing
> senders to directly deliver messages to a particular folder in my mailbox.   For
> example, I want to provide my University with the address
> `ash-AcademicMatters@suugaku.co.uk` to force all their messages into the
> "AcademicMatters" subdirectory.
> 
> Unfortunately,  I  can't  find  any  official  Courier  documentation  regarding
> sub-addressing.  I have found [1], however I'm not sure it will apply  as  I  am
> using virtual mailboxes.

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*.

I'm probably not describing this right, but let's say you've got a small 
business, with a POP3 email account of "business@isp.co.uk". However, 
you've set up a central server with each user having their own account 
eg John, Mary & Sue.

So you configure Sue's mail client to have an address of "Sue 
<sue+business@isp.co.uk>". Out in the internet, smtp servers look at the 
@isp.co.uk bit to deliver it to the right mailserver. Your ISP sees 
"sue+business", *ignores* the bit in front of the plus, and puts it in 
the "business" pop account. Your local mailserver now pulls down the 
email, ignores the bit *after* the +, and shoves it in Sue's email.

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 ...

I don't know what happens with your "-" example, but it just looks wrong 
to me. 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. Internet email addresses and domains are read 
right-to-left (Janet used to be left-to-right, but the Americans won, as 
usual).

Cheers,
Wol