Quoth Philip Hazel on Tue, Sep 14, 1999: > No, you can never be sure. Basically, the use of local nicknames is a
> Bad Thing. However, we all do it! Here in Cambridge, from when we were
> Internet newbies and didn't understand, we have departments whose
> domains are ch.cam.ac.uk and cl.cam.ac.uk, and people sent mail to
> user@??? and user@???. One just has to hope that those xxx names
> don't one day appear in Switzerland or Chile. [snip] > If you really want to be absolutely sure, then you have to have a list
> of your local domains in a file, and run a router that checks that file
> first.
And when these domains do appear, you just have to hope that your
users won't send mail there, or it will arrive to the xxx.ch
subdomain of cam.ac.uk.
[backtrace] > Actually, when the Chilean
> domain first came up, they had a wildcard MX record for *.cl and some
> local mail did disappear into a South American black hole for a while.
So did *.il, long time ago (*.IL IN MX 0 RELAY.CS.NET). See the
Name Server Operations Guide for BIND for details. My boss still
remembers these times :)
We had an even nicer problem. Our users sent mail to <user>@cc,
and the cc TLD has an MX record. It's not a nice thing to do,
because according to RFC 822 (methinks), the domain part of the
e-mail address should comtain at least one period, but Exim 1.9x
did deliver these mails to the cc TLD mailserver (I'm not sure
how Exim 3.0x behaves in these cases).
And, of course, we had a user sending mail to something.md when
he meant something.md.huji.ac.il when the domain something.md
appeared...
