Just as a note to this, we have a DNS (Simple DNS plus) on the same machine as Imail/Declude and point to this DNS. Another DNS server sits on the same 10Mb network whilst the primary is elsewhere. Cuts down on internet look ups.
David WiSS Limited -----Original Message----- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of R. Scott Perry Sent: 19 December 2002 23:49 To: [EMAIL PROTECTED] Subject: RE: [Declude.JunkMail] relays.osiriusoft.com >Declude does a seperate DNS lookup "for each IP4r test for each email" >it is set to check. So if you do 12 different ip4r type tests, 12 DNS >queries are done for each email. Declude either uses the DNS server >you hand code in global.cfg, or it uses the one defined in Imail's SMTP >tab. Correct. >Declude does NOT cache any results from these lookups, but the DNS >server that Declude references DOES cache these lookups - just like any >other DNS lookup - up to it's TTL. Most DNS servers will cache both >positive ("I found an answer") and negative ("no answer was found at >the DNS server") results. Correct. The one catch here is when a single E-mail results in two or more identical queries (for example, with the OSSRC, OSFORM, OSRELAY, etc. tests). In this case, Declude JunkMail makes 3 identical queries (in this case, all would be "1.0.0.127.relays.osirusoft.com", if the IP was 127.0.0.1), which the DNS server may end out 3 times (even though it only needs to be sent out once). The next release of Declude JunkMail will only send out 1 query in this case, which will cut down on DNS traffic slightly. >If your DNS server is local - and your declude is busy - your local DNS >server will have a rich cache of recent lookups it's already done. >relays.osirusoft.com's default TTL is 2 DAYS. That means unless you >set a lower TTL in your resolver, if you recieve 1000 emails from a >certain spammer IP within that two day period, your server will answer >999 of the queries from it's local cache. Declude does not cache, but >if a good percentage of Decludes lookups only involve your 100/1000 LAN >(and not external lookups over the Internet) - performance will greatly >improve. Correct. And a very good explanation, by the way! -Scott --- [This E-mail was scanned for viruses by Declude Virus (http://www.declude.com)] --- This E-mail came from the Declude.JunkMail mailing list. To unsubscribe, just send an E-mail to [EMAIL PROTECTED], and type "unsubscribe Declude.JunkMail". The archives can be found at http://www.mail-archive.com. --- [This E-mail was scanned for viruses by Declude Virus (http://www.declude.com)] --- This E-mail came from the Declude.JunkMail mailing list. To unsubscribe, just send an E-mail to [EMAIL PROTECTED], and type "unsubscribe Declude.JunkMail". The archives can be found at http://www.mail-archive.com.
