Dolly, Mark and Joe Thanks, we found the problem. Checked out our dns settings by going to www.dnsreport.com and it told us that our domain does not support reverse DNS. For some reason our ISP has turned off reverse DNS. Many thanks Simon Whale -----Original Message----- From: Dolly Bareqet [mailto:dolly@xxxxxxxxxxxx] Sent: 19 September 2002 17:03 To: [ExchangeList] Subject: [exchangelist] RE: SMTP error messages - what does this one mean http://www.MSExchange.org/ Hi, Go to http://support.microsoft.com/default.aspx?scid=KB;EN-US;Q284204&ID=KB;EN -US;Q284204 You will find that this article helps you understand NDRs Dolly -----Original Message----- From: simon whale [mailto:simon@xxxxxxxxxxxxxx] Sent: Thursday, September 19, 2002 3:06 PM To: [ExchangeList] Subject: [exchangelist] Smtp error messages - what does this one mean http://www.MSExchange.org/ Hi, Does anybody know what the following smtp error message means and how do I fix it. #5.5.0 smtp;553 sorry, envelope sender must have a valid domain name (#5.7.1) Many thanks Simon Whale ----------------------------------------------------------------------- This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify admin@xxxxxxxxxxxxxxx The views expressed in this email are those of the individual and not necessarily those of UK Data IT This footnote also confirms that this email message has been swept by SOPHOS AV for the presence of computer viruses. ------------------------------------------------------ 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 ------------------------------------------------------ ISA Server Resource Site: http://www.isaserver.org Windows Security Resource Site: http://www.windowsecurity.com/ Windows 2000/NT Fax Solutions: http://www.ntfaxfaq.com ------------------------------------------------------ You are currently subscribed to this MSExchange.org Discussion List as: dolly@xxxxxxxxxxxx To unsubscribe send a blank email to $subst('Email.Unsub') ------------------------------------------------------ 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 ------------------------------------------------------ ISA Server Resource Site: http://www.isaserver.org Windows Security Resource Site: http://www.windowsecurity.com/ Windows 2000/NT Fax Solutions: http://www.ntfaxfaq.com ------------------------------------------------------ You are currently subscribed to this MSExchange.org Discussion List as: simon@xxxxxxxxxxxxxx To unsubscribe send a blank email to $subst('Email.Unsub') ----------------------------------------------------------------------- This email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error please notify admin@xxxxxxxxxxxxxxx The views expressed in this email are those of the individual and not necessarily those of UK Data IT This footnote also confirms that this email message has been swept by SOPHOS AV for the presence of computer viruses.