Exchange 2007 I can't offer much more information at this point. I'm having an issue with an ASP.NET application that is trying to send out an email. The application is writing something like this in the Windows event log on the application server: ...Mailbox unavailable: The server response was 5.7.1 Client does not have permission to send as this sender at... I'm trying to work through the problem, but what is really surprising to me (and the experienced Exchange administrator) is we can't seem to find this error on the Exchange server itself in any of the logs. There is no trace of this connection/communication at all. Is that normal? I'm at the point of setting up a network monitor so we can actually confirm the network connection is occuring. Then I'll move on to concentrating on the ASP.NET application.

That is an SMTP error. Exchange doesn't log everything, particularly if it happening at the SMTP transport layer. Are you authenticating when sending the email? If not then that is probably the issue. It could be caused by a third party tool that is stopping the application from sending the email with the From field populated, could be an anti-spam/anti-spoofing technique. Simon.Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me.

Hi, Have you seen the answer I posted in your pervious thread? http://social.technet.microsoft.com/Forums/en-US/exchangesvrdeploy/thread/5a5b15fd-7e99-4462-96a9-d5f77b68c7b5/#88efabee-d196-40c1-8df0-48b6ee071cc8 If you want the application to send a message through the exchange server, you need to allow the relay for the application server or sending the message by authentication. Allow Anonymous Relay on a Receive Connector http://technet.microsoft.com/en-us/library/bb232021.aspx For sending a message by basic authentication, please refer the following C # code: SmptClinet mySMTP= new SmtpClient (servername, 25) System.Net.NetworkCredential user1= new System.Net.NetworkCredential ("user@domain.com", "Password"); mySMTP.Crendetial=user1 Note: If you use Thomas@domain.com for authentication. The sender email address must be Thomas@domain.com or this user’s alternative email addresses. You also need to check if the basic authentication is enabled on your receive connector: 1. Open EMC, expand to server configuration->Hub transport. In receive connector tab, right click the default receive connector and choose properties. 2. In authentication tab, make sure that Basic authentication is checked and the “Offer Basic authentication only after starting TLS” is unchecked. Gen Lin Forum Support Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com.

That is an SMTP error. Exchange doesn't log everything, particularly if it happening at the SMTP transport layer. Are you authenticating when sending the email? If not then that is probably the issue. It could be caused by a third party tool that is stopping the application from sending the email with the From field populated, could be an anti-spam/anti-spoofing technique. Simon. Simon Butler, Exchange MVP Blog | Exchange Resources | In the UK? Hire Me. I'm able to send a simple email if I try using telnet, and from the error I'm seeing it must be getting to the Exchange server and not getting blocked?

Hi, Have you seen the answer I posted in your pervious thread? http://social.technet.microsoft.com/Forums/en-US/exchangesvrdeploy/thread/5a5b15fd-7e99-4462-96a9-d5f77b68c7b5/#88efabee-d196-40c1-8df0-48b6ee071cc8 If you want the application to send a message through the exchange server, you need to allow the relay for the application server or sending the message by authentication. Allow Anonymous Relay on a Receive Connector http://technet.microsoft.com/en-us/library/bb232021.aspx For sending a message by basic authentication, please refer the following C # code: SmptClinet mySMTP= new SmtpClient (servername, 25) System.Net.NetworkCredential user1= new System.Net.NetworkCredential ("user@domain.com", "Password"); mySMTP.Crendetial=user1 Note: If you use Thomas@domain.com for authentication. The sender email address must be Thomas@domain.com or this user’s alternative email addresses. You also need to check if the basic authentication is enabled on your receive connector: 1. Open EMC, expand to server configuration->Hub transport. In receive connector tab, right click the default receive connector and choose properties. 2. In authentication tab, make sure that Basic authentication is checked and the “Offer Basic authentication only after starting TLS” is unchecked. Gen Lin Forum Support Please remember to mark the replies as answers if they help and unmark them if they provide no help. If you have feedback for TechNet Subscriber Support, contact tnmff@microsoft.com. Yes, I did see your message. From what I can tell, the connector is setup properly, but I fear it is the application that might be trying to do something odd. I'm going to look into the ASP.NET application now. I believe it must be doing something since I have a receive connector configured to allow anon users on port 25, but it does work if I just do a plain telnet connection, but the ASP.NET app still fails.

Try this, create a new receive connector for your ASP.Net app, I assume this is sitting on a server, so add that IP to this new receive connector. Create the connector as per link - http://exchangepedia.com/2007/01/exchange-server-2007-how-to-allow-relaying.html You need to make these change to the connector, for Authentication, Use Basic Authentication only, for permission groups use, Exchange users Only. Dont select anything else. Go to ADSIedit>configuration>Services>Microosft Exchange>Exch Org anme>Exch Admin group>Servers>expand your server>protocols>SMTP receive connectros>select your connector>go to properties>security>click add>add your domain user which you are using in your code Make sure these perissions exisit (allow) for this user>Read,Accept Any Sender,Accept Authoriate Domain Sender,Submit message to any recipient,Submit messages to Server. Click OK to save changes Sukh

Hi, If the telnet works, the problem should be caused by your ASP.Net application. Does the application send the message with authentication? Which authentication method is used by the application? Please also check if the sender email address is correct.