On Mon, Nov 9, 2009 at 1:05 PM, Mike Cardwell
<exim-users@???> wrote:
>>>> We have been using a Barracuda spam appliance delivering to a local mail
>>>> system, and are migrating to hosting user email with Google Apps. We
>>>> will be migrating users gradually, and [...] decided to point our MX records to
>>>> a "front-end" exim box that could do LDAP lookups for recipient
>>>> addresses and send email either directly to Google Apps or to the local
>>>> system via the Barracuda.
>>>
>>> Why not ask Barracuda to forward some of the emails they receive to
>>> Google, and skip the local router?
>>
>> The Barracuda appliance can't do routing based on the local-part, only
>> based on the domain. So whatever it does, it does for our whole email
>> domain (subject to individual user preferences). Hence my desire to
>> front-end it with something more flexible...
>
> Why don't you just switch the two servers around so mail hits the
> Barracuda box first, which then passes it on to the Exim box, which then
> decides if the mail should end up at Google Apps or your local mail
> system...?
That is very likely what I'm going to end up doing.
I was trying to avoid it so that email for users who have been moved
to Google wouldn't be spam-filtered twice (by the Barracuda and then
by Google), using different policies and with different procedures for
quarantine maintenance. My current thinking is to do as you suggest,
and see if there is any way to script an nightly update of the
Barracuda user preferences so that users who have been moved to Google
are individually exempted from the spam scanning. Not having to build
that nightly process seemed to justify the hassle of running the
front-end Exim box, but that was before I appreciated the backscatter
implications.
Most of my other questions about identifying and filtering bounce
messages are intended, at most, as a temporary workaround for a few
days while I test this new configuration. Even if they have no
practical application, Exim is such an incredibly flexible tool that I
was surprised to find something relatively simple that I couldn't
figure out how to make it do. I'm assuming the fault is mine and not
Exim's, and I'd love to correct my ignorance.
Thanks,
-jbp
--
Jay Parker, Systems Manager, UALR Computing Services
jbparker@??? 501-569-3345
http://ualr.edu/jbparker
