[Asrg] On assertions

[der Mouse]

>> I thought one indicated "we receive no mail" by establishing a valid
>> MX record that points to a machine with the smtp port open and a
>> silly little daemon that gives 552 errors in reply to all MAIL FROM
>> commands listening on it.  (would that be a viable commercial
>> service?)
> Depends.  I know of some domains that get several thousand connection
> attempts per second, all spam, when they have an MX.  How much
> bandwidth does your daemon have and how many simultaneous connections
> will it handle?

Several thousand connections per second, at (say) 100 bytes of traffic
each (banner, HELO/EHLO, response, MAIL, response, QUIT, response - if
the responses are short, I don't think 100 bytes total is far off)?

Several hundred thousand bytes per second.  Not over a 10Mbit pipe's
capacity, though approaching it (perhaps even a little over it, given
the various layers' overhead).  Lots of hosting centres can do a 10Mbit
pipe no problem.

Simultaneous connections?  After doing the mail shim for work, I
believe I could build an SMTP daemon which does that; based on some
back-of-the-envelope estimates, simultaneous connections might be a
problem, but probably not requiring more than a little kernel tuning
(and maybe tarting up the machine with RAM, though given modern ideas
of reasonable RAM load, possibly not).

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