Not without a third-party solution, you could take a look at MailEssentials from www.gfi.com or the Open Relay Filter from http://www.vamsoft.com/orf/ Mark Fugatt MCSE, MCT, Microsoft Exchange MVP Pentech Office Solutions Inc Rochester, NY Tel: 585 586 3890 Cell: 585 576 4750 http://www.4mcts.com http://www.exchangetrainer.com -----Original Message----- From: Kelli Irwin [mailto:kelli@xxxxxxxxxxxxxxxxxxxxxx] Sent: Monday, March 22, 2004 10:29 AM To: [ExchangeList] Subject: [exchangelist] Reverse DNS Lookup http://www.MSExchange.org/ Hi All, Is it possible to set up Exchange 2000 to perform reverse DNS lookups AND reject any email that fails? If so, how? Thanks, Kelli ------------------------------------------------------ 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 ------------------------------------------------------