mail service with no mx (was - Re: Computer systems blamed for feeble hurricane response?)

[Roy Badami <roy () gnomon org uk>]

    william(at)elan> Could you elaborate on how firewall will
    william(at)elan> determine if the connection is from mail server
    william(at)elan> or from telnet on port 25?

Perhaps because most telnet clients will attempt telnet option
negotiation?  If so one could avoid this by using a client such as
netcat...

        -roy