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]
