I have three receive connectors: Default (0.0.0.0/0) Internal Anonymous (192.168.1/24) Internal Anonymous Authenticated (192.168.1.101/32) I have a PowerShell script that I have deployed on my Single CAS which needs to send email. My (Single Hub Transport) has all the Recieves for the Organization. When I try to send email I get the following: Exception calling "Send" with "1" argument(s): "The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.1 Client was not authenticated" I understand I need to ensure my CAS connects to a Receive Connector that allows it to bind Anonymously, but send Authenticated email. Which is fine. I can confirm when I try to send email from my CAS through Hub Transport, it goes through "Default" RC which is the reason it doesn't work. From this I have two quick questions: How are clients allocated to a receive connector? Why is my CAS still going to "Default" even though I have specifically added it to It is possible from SendReceive Log files, determine exacrtly what kind of ReceiveConnector can service the request? I THINK the problem I have here is although I have the /32 added into "Internal Anonymous Authenticated", the client is declaring some form of Authentication which is causing it to skip that RC. What's interesting though, I created an identically RC to "Default" except put IPv4 and IPv6 IP's of my CAS, restart MS Transport but it's STILL going to "Default". This has me a bit perplexed.

Hi,When we install Hub server,two receive connetors will be created.Client Servername is used to accept SMTP connections from all non-MAPI clients, such as POP and IMAP.cxfgWhen the emai received by hub,it will use send connector on hub to send to edge server. 5.7.1 Client was not authenticated" indicats that The sender specified in the MAIL FROM field of the SMTP protocol doesn't have permission to submit to this server. The ms-Exch-SMTP-Submit permission must be granted to the sender. So we need to check the permission on this connector. Default Servernameis used toaccept connections from other Hub Transport servers and any Edge Transport servers you have.Understanding Transport Permissions Architecturehttp://technet.microsoft.com/en-us/library/aa997170.aspx Understanding Receive Connectorshttp://technet.microsoft.com/en-us/library/aa996395.aspxRegards,Xiu