Hi Abdul, I'm not John or Mark, but I don't find reverse DNS lookups to be of any value at all. The only thing good about them is that they're nowhere near as malicious as RBLs. HTH, Tom Thomas W Shinder www.isaserver.org/shinder ISA 2004 Beta - Get it now! http://www.microsoft.com/isaserver/beta/default.asp ISA Server and Beyond: http://tinyurl.com/1jq1 Configuring ISA Server: http://tinyurl.com/1llp -----Original Message----- From: Abdul Basit [mailto:binfo@xxxxxxxx] Sent: Friday, February 27, 2004 1:47 AM To: [ExchangeList] Subject: [exchangelist] Reverse DNS Lookup http://www.MSExchange.org/ Hi All, I want to ask you people speciall Mark Fugatt that what do you have opinion about Reverse DNS lookup option in exchange 2000. As i have enabled this option last week to check the ratio of spams. I found good results but recieved calls from diffrent companies that they can't send us emails and their revers dns lookup entry is not yet setup with their ISP. So, I have to disabled it again. What you people have advice for it. Any help will be appreciateable. Thanks Basit ------------------------------------------------------ List Archives: http://www.webelists.com/cgi/lyris.pl?enter=exchangelist Exchange Newsletters: http://www.msexchange.org/pages/newsletter.asp Exchange FAQ: http://www.msexchange.org/pages/larticle.asp?type=FAQ ------------------------------------------------------ Other Internet Software Marketing Sites: Leading Network Software Directory: http://www.serverfiles.com No.1 ISA Server Resource Site: http://www.isaserver.org Windows Security Resource Site: http://www.windowsecurity.com/ Network Security Library: http://www.secinf.net/ Windows 2000/NT Fax Solutions: http://www.ntfaxfaq.com ------------------------------------------------------