Not the best of ideas to drop/dis-allow incoming messages based on no PTR record. Yes, all sending servers should have a PTR record. 1. Auto notices, such as order confirmations, error notifications and so forth often come from web servers or devices that are not internet facing per-se and do not have a PTR record. 2. Depending on volume, checking for a PTR record at the time of and during a incoming transmission can be resource intensive. 3. Not all companies/admins are smart enough to properly configure their configuration and may not have a PTR record. 4. Some ISPs will not create a PTR record for you, or delegate authority to you so you can create the PTR records. (Of course, any one operating an e-mail server should not be using these ISPs, but it does occur.) John Tolmachoff Engineer/Consultant/Owner eServices For You > -----Original Message----- > From: Hermano JS. Queiroz [mailto:hjsqueiroz@xxxxxxxxxxxxxxxxxx] > Sent: Thursday, February 05, 2004 12:23 PM > To: [ExchangeList] > Subject: [exchangelist] DNS Reverse Lookup + Drop connection > > http://www.MSExchange.org/ > > Hi All, > > I would to know if someone can give me a clue about DNS reverse > lookup with exchange. I already check the Perform reverse DNS lookup on > incoming messages (Advanced Delivery) but I really want to drop all > connections that doesn't have their name resolved. Am I dreaming with > something or Exchange 2K SP4 cannot do it or whatelse needs to be done. > > TIA, > > Hermano > > ------------------------------------------------------ > 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 > ------------------------------------------------------