Author: D.M.Chapman Date: To: exim-users Subject: [Exim] bydns_mx (again!) and mbx format questions
[apologies if this hits the list twice - forgot to resub as @kent.ac.uk]
Hi all,
I know this has been raised several times but as I am looking to roll
out Exim 4 onto our main mail machine real-soon-now(tm) I was wondering
if anyone has made any progress on this.
We currently have:
# If it ain't for me, send it to the mail HUB
hub_route:
driver = domainlist
transport = remote_smtp
route_list = "* ukc.ac.uk bydns_mx"
on many mail machines. This works well with <v4 and allows us to add/remove/
generally fiddle with the mx machines as and when we want to. As this config
is on many machines (including some that we don't have direct control over)
it would be nice to replicate this functionality with Exim 4.
Just to complicate things we have currently (and this is likely to get no
better in the short term) at least two groups of machines that really need
to have priorities working.
Is a big help (cheers!) but still has hardcoded machine names/aliases
and when we bring more MX machine into service it will need amending
(annoying on our machines - difficult on machines that we do not manage).
A collegue (fresh from Philips Exim course :-)) has made some progress
using lookup dnsdb but it still has issues and is nowhere near as flexible
as the old bydns_mx option.
RoundRobin dns doesn't have the priority control (list some machines more
than once? Messy).
Running an external program or some perl seems overkill. Searching the list
throws up the suggestion of a cron job that creates (and maintains) a list
of mx machines in a file that we could then use - this sounds promising
but again prioritys may be an issue (multiple files? Eughhh!). Also an
issue of getting all the cron jobs running on all machines (some don't
have perl etc etc).
A final option might be for us to patch the code ourselves to re-introduce
this option. I would rather not do this but can anyone who is more familiar
with the code comment on how feasible this would be? I haven't had to look
at exim source since version 1.92 I seem to remember!
Finally, and changing subject somewhat, as part of the update to v4 on
the main university mailstore I am considering a move to mbx format mail
boxes. A quick play with Exim has proved that this is trivial to set up
but as we are not likely to get as much testing as I would like done on
this are there any gotcha to beware of?
I am hoping to roll this out, convert users inboxes and leave their other
folders in unix format. A quick play with Washington imapd suggests that
this will work but real world feedback would be appreciated. Given the
timescales I am not sure that we want to move to completely new software
so Exim+UWImap solutions are likely to be the only realistic options.
We had hoped that we could get away with doing nothing as PHBs have a
big project to roll out Exchan^H^H^H^H^H^H a new mail system over the next
12 mnths but we have hit the disk IO limit on the current system :-(
