Could it be their server is blocking yours? I would see if you could send this person an email using something like hotmail or from your own person internet connection and see if it bounces or not. If it does I would contact their administrator and enquire why this is happening on their end? Regards, Andrew -----Original Message----- From: Ed [mailto:epollack@xxxxxxxxxxxxxxxxxx] Sent: Friday, December 17, 2004 4:11 PM To: [ExchangeList] Subject: [exchangelist] SMTP communication problem with the recipient's email server http://www.MSExchange.org/ a user recived this message. Is this problem on my end or the reciving end. Your message did not reach some or all of the intended recipients. Subject: RE: LINEAR ACTUATOR Sent: 12/17/2004 3:28 PM The following recipient(s) could not be reached: 'charless@xxxxxxxxxxx' on 12/17/2004 3:30 PM There was a SMTP communication problem with the recipient's email server. Please contact your system administrator. <MBMAIL.**********.com #5.5.0 smtp;550 User unknown - Usuario Inexistente> ------------------------------------------------------ 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: andrew@xxxxxxxxxxxxxxxxxxxxxx To unsubscribe visit http://www.webelists.com/cgi/lyris.pl?enter=exchangelist Report abuse to listadmin@xxxxxxxxxxxxxx