There is one DNS query for every service that you subscribe to for every inbound mail request. That would include "relay" requests. ..of course, the "relay" part of your description is a question... Jim Harrison MCP(NT4, W2K), A+, Network+, PCG http://isaserver.org/authors/harrison/ Read the books! ----- Original Message ----- From: "Work" <wit@xxxxxxxxxx> To: "[ISAserver.org Discussion List]" <isalist@xxxxxxxxxxxxx> Sent: Tuesday, April 09, 2002 3:37 PM Subject: [isalist] Re: Any chance if using SMTP blacklists? http://www.ISAserver.org Have you noticed any overhead on that? We tried it, and and our SMTP relay server started sending delay notifications to some users. ----- Original Message ----- From: "Jim Harrison" <jim@xxxxxxxxxxxx> To: "[ISAserver.org Discussion List]" <isalist@xxxxxxxxxxxxx> Sent: Tuesday, April 09, 2002 1:36 PM Subject: [isalist] Re: Any chance if using SMTP blacklists? > http://www.ISAserver.org > > > Hiya Thor, > > ISA doesn't do anything it wasn't doing before (SMTP server pub in this > case). > I just noticed a hole in the request and thought I'd fill it with the > right solution. > Basically, my mail server does a reverse-lookup on the IP of the sending > host and if it's listed in any one of several relays I use, I reject it > out-of-hand. > I don't have to waste time in the mail router or the virus checker > either; it's just gone. > > ..I lose more spam that way... ;-) > > Jim Harrison > MCP(NT4, W2K), A+, Network+, PCG > http://isaserver.org/authors/harrison/ > Read the books! > ----- Original Message ----- > From: <Thor@xxxxxxxxxxxxxxx> > To: "[ISAserver.org Discussion List]" <isalist@xxxxxxxxxxxxx> > Sent: Tuesday, April 09, 2002 10:10 AM > Subject: [isalist] Re: Any chance if using SMTP blacklists? > > > http://www.ISAserver.org > > > > -----BEGIN PGP SIGNED MESSAGE----- > Hash: SHA1 > > At 09:59 AM 4/9/2002, you wrote: > >http://www.ISAserver.org > > > > > >I use two exclusively: > >http://www.mail-abuse.org > >and > >http://relays.osirusoft.com/ > > > So, what are you doing? You doing a reverse DNS lookup before delivering > the mail? Where does ISA come into play here? > > > -----BEGIN PGP SIGNATURE----- > Version: PGP 7.1 > > iQA/AwUBPLMgj4hsmyD15h5gEQJFpACgq3zeY8eyvK0Lb5fu8ahhL0S0gb8An3BX > IKiZBlGPbfqk6/iCquKNHyxx > =JOTt > -----END PGP SIGNATURE----- > > ------------------------------------------------------ > You are currently subscribed to this ISAserver.org Discussion List as: > jim@xxxxxxxxxxxx > To unsubscribe send a blank email to $subst('Email.Unsub') > > > > ------------------------------------------------------ > You are currently subscribed to this ISAserver.org Discussion List as: wit@xxxxxxxxxx > To unsubscribe send a blank email to $subst('Email.Unsub') ------------------------------------------------------ You are currently subscribed to this ISAserver.org Discussion List as: jim@xxxxxxxxxxxx To unsubscribe send a blank email to $subst('Email.Unsub')