[Pkg-exim4-users] oddball network setup

[Ross Boylan]

I currently want to set up my machine, iron, as follows:
1. iron.psg.net is FQDN.  Reverse lookups on this name will fail.
2. mail that leaves the box from auser should appear to be
auser at biostat.ucsf.edu in all relevant headers and SMTP envelopes
(alternately, might limit this to specified users, i.e., myself.  But
that raises the issue of appropriate return edress for other users.  The
only users likely to generate outbound mail have appropriate biostat
addresses, I think.).
3. All mail to me must go to ross at biostat.ucsf.edu, on a different
machine.  I pull it from there via fetchmail.
4. System operations continue to generate local mail.

Here's my plan.  If anyone could tell me if it will work, and if it's
the best way to do things, I'd appreciate it.

My network environment will change in the future in many ways.  I note
in particular that things are not stable enough that using the
biostat.ucsf.edu machine as a smarthost (if I understand that term--I
mean having all outgoing mail go through it) seems wise.

Getting a FQDN was a challenge; I edited /etc/hosts and gave the name to
the external IP address, and that seemed to do the trick.  iron has no
local DNS running.

etc/hostname
------------
iron

etc/mailname
-------------
iron.psg.net 
# currently just iron
# could this be blank?  or biostat.ucsf.edu?  iron.biostat.ucsf.edu?
# There is a machine named biostat.ucsf.edu, and it's not iron.



update-exim4.conf.conf
----------------------
dc_eximconfig_configtype='internet'
dc_other_hostnames=''
dc_readhost='biostat.ucsf.edu'
# not clear readhost works for configtype='internet'
dc_relay_domains=''
dc_minimaldns='false'
dc_relay_nets=''
dc_smarthost=''

dc_local_interfaces='127.0.0.1.25:127.0.0.1.26'
# port 26 for use by fetchmail, to let me distinguish it from others
# omission of public interfaces deliberate
CFILEMODE='644'
dc_use_split_config='true'
dc_hide_mailname=''
# hide_mailname irrelevant for 'internet'
dc_mailname_in_oh='true'

# or do I need an explicit rewriting section?

*If* that works then it would be nice to make all mail sent to
ross at biostat.ucsf.edu delivered locally, rather than making a roundtrip
through that server.  Based on
http://exim.stanford.edu/exim-html-4.40/doc/html/FAQ.html#TOC117
the recommendation seems to be treat biostat.ucsf.edu as remote, and
pick off what I need.  (This may collapse if my FQDN laters becomes
iron.biostat.ucsf.edu, but one problem at a time.)  This needs to go
before the SMTP routing at router/200_exim4_config_primary.  It probably
should go before the other routers, though I don't think they're
relevant for me.  I deliver to cyrus

router/050_rb_grab
------------------
   farisnear:
     debug_print = "R: farisnear for ross at biostat.ucsf.edu"
     driver = accept
     domains = biostat.ucsf.edu
     local_parts = ross
     transport = cyrus

The transport sets the user.  I'm puzzled the FAQ didn't suggest using
user in the router (farisnear above) itself.  Wouldn't that work?

I spent some time looking at how I could rewrite and bounce to an
appropriate router, but wasn't quite sure how to do so.

BTW the cyrus delivery causes both a local delivery to the IMAP server
and forwards the message to another system, so the same message will
reappear in exim as an outbound one.  The other system is safely remote.
-- 
Ross Boylan                                      wk:  (415) 514-8146
185 Berry St #5700                               ross at biostat.ucsf.edu
Dept of Epidemiology and Biostatistics           fax: (415) 514-8150
University of California, San Francisco
San Francisco, CA 94107-1739                     hm:  (415) 550-1062