Not to mention the extra time it takes resolving it on each and every incoming email. Well, I guess there IS the local DNS cache, so if most of your mail comes from a core group of customers, no big deal. But it WILL slow down your SMTP services.
-tom > -----Original Message----- > From: Roger Seielstad [mailto:[EMAIL PROTECTED]] > Posted At: Wednesday, November 21, 2001 09:56 AM > Posted To: MSExchange Mailing List > Conversation: Verify Sender > Subject: RE: Verify Sender > > > Before you go hog wild with this, we've enabled this > functionality (with our > Unix relays, not Exchange) more than once. > > I would estimate that 20-30% of the mail hosts that try to > pass mail have > misconfigured DNS, and depending on how strict the option is, > that means > that 20-30% of your inbound mail could be rejected. > > ------------------------------------------------------ > Roger D. Seielstad - MCSE MCT > Senior Systems Administrator > Peregrine Systems > Atlanta, GA > http://www.peregrine.com > > > > -----Original Message----- > > From: Murphy, Brian [mailto:[EMAIL PROTECTED]] > > Sent: Tuesday, November 20, 2001 3:37 PM > > To: Exchange Discussions > > Subject: RE: Verify Sender > > > > > > Yes........RDNS........ I'm running Exc 5.5 SP4. > > > > Users... what is that? > > > > -----Original Message----- > > From: Tom Meunier [mailto:[EMAIL PROTECTED]] > > Sent: Tuesday, November 20, 2001 2:26 PM > > To: Exchange Discussions > > Subject: RE: Verify Sender > > > > > > What version of Exchange? If I'm understanding you > > correctly, you want > > to do an RDNS lookup on the incoming IP address, and verify > that's the > > domain that's talking to your SMTP box. E2k can do it; I > > don't use the > > functionality so I can't remember whether Ex5.5 can. The > downside is > > you'll start rejecting everyone whose RDNS isn't correctly > configured, > > which is a whole bunch of people. Your users will begin to > blame you; > > they don't want to hear about yadda yadda RDNS yadda yadda properly > > configured blah blah the CEO's home ISP blah blah. > > > > -----Original Message----- > > From: Murphy, Brian [mailto:[EMAIL PROTECTED]] > > Posted At: Tuesday, November 20, 2001 2:27 PM > > Posted To: MSExchange Mailing List > > Conversation: Verify Sender > > Subject: Verify Sender > > > > > > Is there a way to get Exchange to validate sender's address prior to > > delivery to internal valid user. In other words, is there a way to > > validate the sender's domain is legit. > > > > Example: > > I have setup a standalone Exchange box that is configured to reroute > > incoming smtp but has routing restrictions enabled. However > > then box is > > setup to "relay" for my domain only. The system is configured to > > "Forward all messages to host" (my other Exchange Server). > > > > The other Exchange server is setup to "Reroute incoming SMTP > > mail" with > > Routing restrictions enabled. However, this box is setup > to route my > > domain inbound. > > > > The routing works as anticipated. However, I can still > > "dupe" my return > > address. I want to create a mechanism that also checks the > > validity of > > the sender prior to delivery. > > > > _________________________________________________________________ > > 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] > > > > _________________________________________________________________ > > 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] > _________________________________________________________________ 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]
