Re: [SLUG] Sending mail from within a highly locked down network

["Matt Hope" <matt.hope@xxxxxxxxx>]

On Mon, Apr 21, 2008 at 12:06 PM, Mary Gardiner <mary@xxxxxxxxxxxx> wrote:
> Background: my normal mail setup uses Postfix on my laptop to send
>  outgoing mail. My university has blocked all outgoing ports except 80
>  (and they may have a transparent proxy in front of that) and 443 on
>  their wireless network. My laptop cannot contact its normal mail servers
>  on any port. (I happen to run those servers, but I already have
>  processes listening on 80 and 443 on the relevant servers!)

Some ideas I've had:

#1
Okay, so a bit unusual, but if you have a script in if-up.d that runs
nsupdate to update a local copy of bind, you'll always have a DNS name
that points to your nearest mail exchange

#2
Playing with DNS and search paths such that
smtp-forwarder.$any_domain_i_frequent exists, and using
"smtp-forwarder" as SMTP relayhost.

#3
Using deeper perl-foo in exim4, and doing like Peter suggests, but
consulting a file, that lists network masks and appropriate relay
hosts

lookup{ net-lsearch;$some_foo }{ CONFDIR/relay_by_domain }