Hii have a problem with sending mails to a specific domain.We have a static ip and Exchange 2003 with SP2.If i send a mail there i will get the follow answer:You do not have permission to send to this recipient. For assistance, contact your system administrator. <server.domain.de #4.7.1 smtp;450 4.7.1 <server.domain.de>: Helo command rejected: Host not found>At this exc-server we maintain three domains: domain.de, domain-wood.de and domain-authority.de. It will be sended by domain-wood.de but in error description we have domain.de as domain. Is this a possible error-source or do anybody know the real reason or have an idea?Thanks for helpD. Forschteufel software GmbH

Check a few things with your DNS: The reverse DNS (rDNS \ PTR) record is configured by the people who issued your IP address in most instances (so your ISP). Below are two articles which explain the general requirements for reverse dns (rDNS\PTR) records for your IP address. I try to adhere to the following when setting up a rDNS (PTR) record: Be a Fully Qualified Domain Name (FQDN) such as server.domain.com (not just 'domain.com' or 'server'). Should not contain 'in-addr-arpa' and should not include words like pool or dyn etc.Should match what you use in your SMTP HELO\EHLO hostname if possible. For neatness and as a good rule of thumb, if your incoming mail is delivered to the same server that you use for Outgoing you should make sure all the following FQDN's match: MX recordrDNS (PTR) recordSMTP EHLO hostname http://www.simpledns.com/kb.aspx?kbid=1052 http://postmaster.aol.com/info/rdns.html http://www.amset.info/exchange/dnsconfig.asp (Courtesy of EE member Mestha)

On Thu, 25 Feb 2010 16:56:41 +0000, TS-Forsch wrote:>>>Hii have a problem with sending mails to a specific domain.We have a static ip and Exchange 2003 with SP2.If i send a mail there i will get the follow answer:You do not have permission to send to this recipient. For assistance, contact your system administrator. >><server.domain.de #4.7.1 smtp;450 4.7.1 <server.domain.de>: Helo command rejected: Host not found>At this exc-server we maintain three domains: domain.de, domain-wood.de and domain-authority.de. It will be sended by domain-wood.de but in error description we have domain.de as domain. Is this a possible error-source or do anybody know the real reason or have an idea?Thanks for helpD. Forschteufel software GmbH Does the name used by your server in the HELO command exist in apublic DNS? It looks like you're failing a simple forward lookup ofthat name.---Rich MatheisenMCSE+I, Exchange MVP--- Rich Matheisen MCSE+I, Exchange MVP

The error "Helo command rejected: Host not found" can cause by the HELO domain check by recipient side. Recipient’s mail server will double-check the domain name following HELO command with internet DNS query to see if it's a valid FQDN (server.domain.de). If it’s not registered on your ISP DNS yet, recipient domain can suspect it's spam mail source and finally reject the connection. So, besides the PTR troubleshooting as said by Shaun, please also check the FQDN in the SMTP virtual server Resources: Troubleshooting Mail Flow and SMTP FQDN in the Default SMTP Virtual Server Properties of Exchange 2003 Changing the fqdn and masquerade domainJames Luo TechNet Subscriber Support (http://technet.microsoft.com/en-us/subscriptions/ms788697.aspx) If you have any feedback on our support, please contact tngfb@microsoft.com