[Kolab-devel] Kolab2 Distribution lists using alias_maps instead of virtual_maps

[Matt Douhan]

On Tue March 29 2005 17:10, Stephan Buys wrote:
> Another issue:
>
> kolabfilter_destination_recipient_limit = 1
>
> in main.cf.template basically expands _any_ multi-recipient message that
> Kolab2 recieves into seperate emails for each recipient.
>
> What does this mean?
>
> If user A sends a mail to user B, C and D.
>
> Postfix will hit the filter/amavis/etc 3 times, once for each message.
> *It will then deliver messages to Cyrus 3 times, bye-bye single instance
> storage - trippling the amount of space used by the email on the server.
>

We had problems with this scenario when restoring backups of crashed servers, 
the issues we saw was that emails was "lost" i,e it seemed like the links 
created were lost during restore operations.

This may have been due to the backup program in use (Legato) but still, disk 
is cheap these days.

> Scenario2:
>
> User A sends an email to _external_ users B, C and D at the same external
> mail server.
> **Instead of sending a message once to multiple recipients (SMTP supports
> this) it will use 3 times the amount of bandwidth as a copy of the message
> is sent to the external server separately. Even if using a smart/relay
> host.


if this can be done without (1) above, then it is a cool feature, if not then 
I rather waste the bw for the same reason as above.

>
> Postfix then sorts out which messages to expand or which ones to deliver
> locally. Smart-host performance is also badly affected by the current
> setting.

I will do some additional tests with backup/restore again to see if our 
problems were any of the following.

1. User error on our part.

2. Legato issues

I will also try different means of backup, simple tar/dump as well.

But if the choice is between performance and reliability I think choosing the 
latter would cause less issues in the long run.

rgds

Matt


>
> On Tuesday 29 March 2005 16:36, Bernhard Reiter wrote:
> > HI Stefphan,
> > those are questions for Steffen. :-)
> >
> > On Tuesday 29 March 2005 14:16, Stephan Buys wrote:
> > > Should the Kolab2 server not rather use postfix virtual_maps for
> > > distribution list expansion instead of alias_maps. IIRC alias_maps are
> > > used only during local delivery which implies that recipients on
> > > non-local homeservers will not get the messages delivered to it.
> > >
> > > Virtual maps will expand the distribution list on the server and then
> > > send it out to other homeservers as well as trigger local delivery for
> > > the relevant boxes.
> > >
> > > Also, the ldap searchstring of (|(cn=%u)(cn=%s)) makes a lot more sense
> > > in main.cf.template?
> > >
> > > Also, has anyone noticed my issue
> >
> > Which one in particular?

-- 
Matt Douhan
www.fruitsalad.org
kolab2 + kontact + toltec == success
Now lets get Horde into shape mmkay