I have seen misleading 550 errors if Reverse DNS to your domain is not correct. If the IP address of your SMTP relay/server resolves to mail.domain.com, but the SMTP server/relay actually claims to be a different host name, then you can get a 550 error.
-Kevin > -----Original Message----- > From: Jeffrey Dubyn [mailto:[EMAIL PROTECTED]] > Posted At: Wednesday, February 12, 2003 5:42 AM > Posted To: Exchange > Conversation: Strange 550 error > Subject: Strange 550 error > > > I have an issue with an Exchange 2000 SP3 server where an > email sent from > inside the Exchange organization is not getting to some > recipients in a > specific domain. I have logging turned up, and found a > strange message: > > 550+not+local+host+recipientdomain.com,+not+a+gateway > > The 550 error maps to a generic protocol error (SMTP error), > but I can't > make heads or tails out of the rest of the message. > > What is strange is that the domain comes up successfully in > nslookup and > from the Exchange server, I can connect via telnet to port > 25. The users > have had no trouble sending email to this recipient at this > domain before or > since, except for this most important email (or course). > There was no NDR, > no nothin' - just seems like the email went into a black hole. > > Thanks for any assistance! > > > _________________________________________________________________ > List posting FAQ: http://www.swinc.com/resource/exch_faq.htm > Archives: http://www.swynk.com/sitesearch/search.asp > To unsubscribe: mailto:[EMAIL PROTECTED] > Exchange List admin: [EMAIL PROTECTED] > _________________________________________________________________ List posting FAQ: http://www.swinc.com/resource/exch_faq.htm Archives: http://www.swynk.com/sitesearch/search.asp To unsubscribe: mailto:[EMAIL PROTECTED] Exchange List admin: [EMAIL PROTECTED]