Sounds like they need to authenticate to the Exchange server. John T eServices For You -----Original Message----- From: Praveen Ramaswamy [mailto:ramaswamy_praveen@xxxxxxxxx] Sent: Friday, July 15, 2005 7:07 AM To: [ExchangeList] Subject: [exchangelist] SMTP issue http://www.MSExchange.org/ Hi, Users are not able to send external mails while using outlook express but can send external mails using Outlook MAPI client. I am forwarding all external mails to smart host from my backend server. What should I do to allow external mails from internet clients like Outlook express?? I am running exchange 2003 sp1 and sendmail on linux. Regards Praveen R _____ Start <http://us.rd.yahoo.com/evt=34442/*http:/www.yahoo.com/r/hs> your day with Yahoo! - make it your home page ------------------------------------------------------ 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: World of Windows Networking: http://www.windowsnetworking.com 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 ------------------------------------------------------ You are currently subscribed to this MSEXchange.org Discussion List as: johnlist@xxxxxxxxxxxxxxxxxxx To unsubscribe visit http://www.webelists.com/cgi/lyris.pl?enter=exchangelist Report abuse to listadmin@xxxxxxxxxxxxxx