Peter Salzman wrote:
> Hi all,
>
> I have DSL with dynamic IP. A domain name is attached to my IP, and I wrote
> a Perl script that updates my DNS whenever that IP address changes.
>
> Unfortunately, my ISP filters incoming port 80 and outgoing port 25 if the
> "from" header doesn't contain a "verizon.net" address.
>
> Currently, I receive email at my home computer, but have to ssh to a
> friend's machine to send email. It would be much more convenient if,
> instead of sshing to his computer to use mutt, I could use mutt from my home
> machine and use his machine as an SMTP server.
>
> I read the Exim docs
>
> http://www.exim.org/exim-html-3.20/doc/html/spec_46.html#SEC813
>
> and I believe this is called "outgoing relaying".
>
> The docs say that in order for my friend's computer to be an SMTP server for
> my computer, he needs to add this:
>
> host_accept_relay = ip_address/netmask
>
> to a configuration file. A few questions about this:
>
>
> 1. Since I have a dynamic IP but a constant domain name, can this directive
> use domain names like this:
>
> host_accept_relay = mail.wavefunction.org
>
> 2. Are there any security considerations to be made with this?
>
> 3. What config file should this go in?
>
>
> Thanks!
> Pete
>
>
Hi Pete,
If you and your friend can both run a recent version of Exim 4 the
following document may help. It might not be exactly want you want but
you should be able to get an idea of whats required.
http://www.exim-new-users.co.uk/Integrating_Exim_with_Exchange_Tutorial_v.1.1.pdf
Your friend will use the "Option1 : straight delivery via MX records"
more commonly known as the "dnslookup" version.
He will need to add your domainname to his
"exim-accept-mail-from-this-list-of-ip-addresses" (although your adding
a domainname not an ip address)
Optional: He *might* also need to add your domainname to
"exim-accept-for-this-list-of-domains" (if he is also going to also
collect all mail for you in future)
You will use "Option2" and use him as a smarthost for sending out all
"non-local" e-mails
You will need to add his IP Address or fully qualified domainname to
your "manualroute" router in this configuration.
Optional: You *might* need to add his IP address to your
"exim-accept-mail-from-this-list-of-ip-addresses" (if he is also going
to collect and manualroute all mail for you in future)
This isn't a standard config and the filenames are not part of a default
exim config. It was written as a tutorial to help people setup a
mail-hub in the DMZ to send and receive all mail for an exchange server
on the LAN. In your situation your friend becomes the mail-hub and you
are the exchange server (take a deep breath). It is completely up to you
if you receive e-mails directly or via him, depends if you just wan to
use him as an "outbound relay" or as a full "mail-hub" for all inbound
and outbound mail.
Some people use the term "smarthost" for this facility, try googling on
that too.
Hope that helps, just reply if you need any further assistance.
If you check back on my site later in the week I should have a updated
paper and these configs downloadable as an RPM.
(Thanks to Tim Jackson and David Woodhouse for the help and advice
building RPMS this week)
Thanks
Jason_Meers
--
www.exim-new-users.co.uk
