[NTLUG:Discuss] Need advice: hosting email at home

[Michael Patrick]

On Fri, Apr 19, 2002 at 05:10:17PM -0500, Travis Bell wrote:
> Greetings fellow NTLUGers, I was wondering if I might pick your brains.
> 
> I want to host my email on my home server.  This machine is on battery backup
> and losing power isn't a problem unless the power goes out for an extended
> period of time.  The one problem I could face is that I'm on AT&T Broadband
> and they have changed to using DHCP.  However, in the entire time since they
> changed this policy, my IP has never changed.  Whether this has to do with the
> server never rebooting or them setting insanely long leases I do not know.
> 
> On to my question: What is the best route to take to ensure that I don't lose
> email in the case that either my connection goes down or my IP actually does
> change (whilst I change my DNS records)?  What potential problems exist that I
> haven't thought of when using my idea listed below?
> 
> This is what I figure I should do:
> Primary NS: ns1.granitecanyon.com (service restarted every 24 hours)
> * Have 2 MX records
>   - List my server as highest priority
>   - List a friend's mailserver (on NT - blech) as next priority
> Secondary NS: ns2.granitecanyon.com
> * Same as Primary NS
> 
> With this setup is there a way to have the secondary mail server move mail
> back to my server once it's back up?  When you have 2 MX records, does that
> mean it will always send to highest priority unless it can't, or would some
> mail go to the next server even if mine is up?  Should I change one of my Name
> Servers to my server or leave them at granitecanyon.com?  Any and all
> suggestions are welcome!
>

If you have one of the MXs as preference 10 and one as 20 other mail servers will try to contact the pref 10 server first; failing that they would talk to the pref 20 machine.  As for getting mail from pref-20 to pref-10 once 10 comes back up... that depends on the software.  My backup MX just sticks the mail in its queue and tries to resend periodically.  You might also look at whether your friend's server supports ETRN.

As for the DNS servers... I'm kind of split... on the one hand it is good to have them at granitecanyon (reliable networking) but I don't like having all the dns servers in one place.  If it were me, I think I'd have one on the cable line, just in case granitecanyon did nuke a router or something.


Michael