Re: [Exim] Re: Bagle, unqualified HELO, time delays

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Autore: Fred Viles
Data:  
To: exim-users
Oggetto: Re: [Exim] Re: Bagle, unqualified HELO, time delays
On 4 Mar 2004 at 9:52, James P. Roberts wrote about
    "Re: [Exim] Re: Bagle, unqualified H":


|...
| Would it make sense to apply a 30 second-ish delay to every incoming
| connection, simply to weed out the virii? Since any legit MTA should accept
| such a delay without incident, and most virii engines would give up.


No, I think that would be very anti-social behavior. Imagine if
everyone did it - what would happen to the Internet's email
infrastructure?

| After a little thinking, it occurs to me, this could work even for some
| high-volume servers.


You're only thinking about the effect on the recipient server. The
problem is the effect on all the legitimate sending servers.

IMO, artificial delays should be introduced into the SMTP session
*only* if there is already good reason to suspect that the sender is
not legitimate. Then the benefit outweighs the infrastructure cost
(IMHO).

Alan's approach is a good example.

- Fred