Compiling on Windows, and a question of policy

Vernon Schryver
Mon Dec 2 16:16:34 UTC 2002

> From: "John R Levine" <>

> ...
> I'm considering building a lowish end mail appliance using DCC, but if I
> do, it'll be running something unixish so it can run its own server, and
> I'd charge a monthly maintenance fee which would include access to other
> servers.
> ...

The 15-bit DCC server-ID makes having a zillion small servers impossible
without using uglinesses such as the server-ID translation kludge.
However, a low-end appliance could pay for the use of external servers.
I think there's enough de facto load balancing in the protocol and
the client code to make this work fine.  Each DCC client tracks up to
8 server names and the current DCC RTTs for as many as 16 IP addresses
among those names.  If you spread the servers around, the appliance
would either be able to see servers on the Internet or would not see
much mail to filter.

The current daily bandwidth required for DCC flooding is similar
to the bandwidth needed to check about 100,000 mail messages/day.
A DCC server wants about 128 MByte of RAM to start and perhaps
another 50 MByte per 100K mail messages/day.  See

Vernon Schryver

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