Re: [exim] Nhash and Imap

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Author: Torsten
Date:  
To: exim-users
Subject: Re: [exim] Nhash and Imap
Thank you very much, Bill.

This was really what I was searching for.
I can`t remember "Dovecot", sounds good. I was testing Courier a few
month ago, so I give Dovecot a try and test this scenario.


P.s.: The reason why I was asking for this: We want to scale our
Mailsystem to support more users by using GFS (loadbalanced
active/active clustering) and migrate from POP3 to IMAP. RedHat support
was telling me that splitting up maildirs is recommended because of
performence issues. Let`s see.


Thanks
Torsten


Am Freitag, den 02.02.2007, 20:16 +0800 schrieb W B Hacker:
> Torsten wrote:
> > Just to make at clear.
> > I want exim to store mails like this:
> > file = "/var/mail/${nhash_127:$local_part}/$local_part/INBOX"
> > So if I understood it right, Exim builds a hash from "$localpart" and builds
> > a directory structure like this:
> > /var/mail/0/totty or /var/mail/127/bill
>
> Not hard. Just an extra level to what is already done.
>
> Exim writes where it is told to write - fixed or 'calculated'.
>
> >
> > How can the Imap daemon know where to find the maildir for Totty or Bill?
> > Is there a buildin hash tool or something like that?
>
> The IMAP daemon reads where it is told to read - fixed or 'calculated'.
>
> Both can be driven 100% from a file, table, or DB, 100% 'calculated', or any mix
> of the two that their respective variables and string-manip tools can stand.
>
> (NB - Exim and Dovecot play very well together on that score - similar conventions).
>
> All you need to do is insure that Exim and the IMAP daemon either use the same
> 'hard coded' record or parts thereof, and/or perform the same calculation.
>
> Inserting hash or other functions is not greatly different from the use of
> $local_part and $domain as 'variables'.
>
> Note that w/r the use of a 'computed' location - hash or otherwise - neither has
> to understand it - merely be assured of generating the same one.
>
> Or NOT [1]
>
> > I searched a lot, but I couldn`t get an answer how Courier, Cyrus or other
> > MUA`s handle that directory structure.
> >
>
> Much the same as any other, really. It is just an added level in an
> already-multi-level dirtree.
>
> > Thanks
> > Torsten
> >
>
> HTH,
>
> Bill
>
>
> [1] CAVEAT: Not a general-purpose recommendation.
>
> We use SQL selects, and Exim & Dovecot *may* be set to see the storage
> differently, as their records are synced by choice.
>
> Or not.
>
> This allows us to share incoming across departmental or functional lines,
> (Helpdesk, NOC), transparantly alias, forward, duplicate, auto-respond,
> sub-sort, quarantine, 'hand over' the correspondence history of a departing
> staff member to their replacement, and selectively archive - all w/o touching
> the Exim configure or re-HUp'ing.
>
>
>
>
>
>
>
> >
> >> Your IMAP daemon's docs are your starting point.
> >>
> >> 'basics' - so long as the folders are under the appropriate Maildir for a
> >> given
> >> user, with the same perms, AND the MUA is NOT limited to 'show subscribed
> >> folders only' Dovecot, to name one, picks them up.
> >>
> >> Courier-IMAP is a little pickier about where they are (under INBOX) and
> >> whether
> >> they have a "." prefix.
> >>
> >> Bincimap, GW-IMAP, Cyrus, and others I haven't had hands-on for several
> >> years.
> >>
> >> In all cases, just configure Exim to name and drop with whatever the IMAP
> >> daemon
> >> expects.
> >>
> >> HTH,
> >>
> >> Bill
> >>
> >> --
> >> ## List details at http://www.exim.org/mailman/listinfo/exim-users
> >> ## Exim details at http://www.exim.org/
> >> ## Please use the Wiki with this list - http://www.exim.org/eximwiki/
> >>
> >
> >
>
>