You are on a black list. It looks your domain has got on to the Blacklist rather than the IP address. Try putting both the domain name and your public IP address in to this web site and see if you are listed. http://rbls.org/ If you are listed you will have to check the web site of the blacklist to see how about getting de-listed. As a short term measure, configure an SMTP Connector to route email through your ISP's SMTP server. http://www.amset.info/exchange/smtp-connector.asp Simon. -- Simon Butler MCP, MCSA, MVP:Exchange Senior Systems Administrator Amset IT Solutions Ltd. e: simon@xxxxxxxxxxxx w: www.amset-it.com w: www.amset.info ________________________________ From: Mohammed Naimathullah Siddiqui [mailto:mailnaimathullah@xxxxxxxxx] Sent: 05 October 2005 11:53 To: [ExchangeList] Subject: [exchangelist] Outgoing E-mails Problem http://www.MSExchange.org/ Hi, I hope all are fine, we have exchange 2003 DC and also exchange 2003 server and we are using GFI mail essential for downloading e-mails form our hosting company. We have configured two domain names in it xyz.com and abc.com it was working fine 2 months, but now we are facing the problem in sending e-mail when we send any e-mail to hotmail,yahoo and gmail it is going but others it is not going. After staying in the SMTP queue e-mails are returning back with this message. Your message did not reach some or all of the intended recipients. Subject: FW: API-570 Marks Sent: 10/3/2005 12:29 PM The following recipient(s) could not be reached: '123@xxxxxxxxxx' on 10/3/2005 12:29 PM There was a SMTP communication problem with the recipient's email server. Please contact your system administrator. <exchange.Al-Subeaei.com #5.5.0 smtp;550 Denied by policy: Sender is listed on DNS-based RBL.> Can help me in this problem because now every e-mail is returning with this message. Regards Siddiqui ------------------------------------------------------ List Archives: http://www.webelists.com/cgi/lyris.pl?enter=exchangelist Exchange Newsletters: http://www.msexchange.org/pages/newsletter.asp ------------------------------------------------------ Visit TechGenix.com for more information about our other sites: http://www.techgenix.com ------------------------------------------------------ You are currently subscribed to this MSEXchange.org Discussion List as: exchange-list3@xxxxxxxxxxxx To unsubscribe visit http://www.webelists.com/cgi/lyris.pl?enter=exchangelist Report abuse to listadmin@xxxxxxxxxxxxxx