You can't block it. Mark Fugatt MCT, MCSE, Microsoft Exchange MVP Pentech Office Solutions Inc Tel: 585 586 3890 Cell: 585 576 4750 Fax: 585 249 0316 MSN IM: mark@xxxxxxxxx www.4mcts.com www.exchangetrainer.com -----Original Message----- From: Victor Naranjo [mailto:vnaranjo@xxxxxxxxxxxxx] Sent: Wednesday, December 03, 2003 12:14 PM To: [ExchangeList] Subject: [exchangelist] RE: how to block SMTP Commands without ISA Server http://www.MSExchange.org/ I can connect to Exchange Server doing telnet session to port 25 and execute commands like, helo domain, mail from, etc and send a message to an internal mailbox making impersonation . This is a security issue, how to block this smtp commands is anybody make a telnet session to port 25? -----Original Message----- From: Mulnick, Al [mailto:Al.Mulnick@xxxxxxxxxx] Sent: Wednesday, December 03, 2003 11:48 AM To: [ExchangeList] Subject: [exchangelist] RE: how to block SMTP Commands without ISA Server http://www.MSExchange.org/ Can you give an example of what you want? I suspect that blocking commands means one thing to you and something different to me. I think of blocking commands as disabling verbs. I suspect you want to block specific users from sending you email. A deny or block list. Al -----Original Message----- From: Victor Hugo Naranjo [mailto:vnaranjo@xxxxxxxxxxxxx] Sent: Wednesday, December 03, 2003 11:40 AM To: [ExchangeList] Subject: [exchangelist] how to block SMTP Commands without ISA Server http://www.MSExchange.org/ Help with this... =20 In Exchange 5.5, 2000 and 2003 how to block SMTP Commands without ISA = Server? If the Mail from: (SMTP Command) is blocked, Can I still receive Internet eMails? Victor Naranjo CONSULTANT SYNERGY ------------------------------------------------------ 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 ------------------------------------------------------ ------------------------------------------------------ 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 ------------------------------------------------------ ------------------------------------------------------ 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 ------------------------------------------------------