DNS really isn't that big a deal, and caching helps a lot
------------------------------------------------------ Roger D. Seielstad - MCSE MCT Senior Systems Administrator Peregrine Systems Atlanta, GA http://www.peregrine.com > -----Original Message----- > From: Tom Meunier [mailto:[EMAIL PROTECTED]] > Sent: Wednesday, November 21, 2001 2:38 PM > To: Exchange Discussions > Subject: RE: Verify Sender > > > 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] > _________________________________________________________________ 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]
