>From the previous use of reverse DNS lookups, I think its safe to say that about 25% of companies, including some who should know better, have misconfigured DNS entries. We found it to be more trouble than it saved - the only spam you'll consistently stop with it is that which originates from dial up connections and probably some DSL/Cable Modem pools, but not always.
------------------------------------------------------ Roger D. Seielstad - MCSE Sr. Systems Administrator Inovis - Formerly Harbinger and Extricity Atlanta, GA > -----Original Message----- > From: Clemens, Rick [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, January 15, 2003 6:13 PM > To: Exchange Discussions > Subject: IMSS SMTP Server Question > > > IMSS which is the next version of Trend Micro's Virus Wall > provides the > ability to do reverse DNS lookups. It is my understanding > that this will > help reduce SPAM from bogus addresses but will require more > CPU resources to > accomplish. > > My question is is anyone else using Reverse DNS Lookup's? > And what happens > when a companies SMTP server is NAT'd behind a firewall and > port 25 is just > passed on to the internal SMTP server? > > The problem being that their External MX record will point to > the Firewall > but the SMTP packet will reflect the actual SMTP server name > internally......When My SMTP server tries to reverse DNS > lookup on it....it > will not be able to resolve and My company will not be able > to send e-mail > back and forth with this company. > > Am I stating what happens correctly? > > _________________________________________________________________ > List posting FAQ: http://www.swinc.com/resource/exch_faq.htm > Archives: http://www.swynk.com/sitesearch/search.asp > To unsubscribe: mailto:[EMAIL PROTECTED] > Exchange List admin: [EMAIL PROTECTED] > _________________________________________________________________ List posting FAQ: http://www.swinc.com/resource/exch_faq.htm Archives: http://www.swynk.com/sitesearch/search.asp To unsubscribe: mailto:[EMAIL PROTECTED] Exchange List admin: [EMAIL PROTECTED]
