Update: Beginning yesterday, November 14, 2008, the smtpauth.sbcglobal.net email relay servers began NDRing emails sent from AT&T customers. Again, this information was not passed on to its customers.
I've updated the instructions below to use the smtp.att.yahoo.com servers, which are now accepting authenticated connections.
First, let me say that SBC Yahoo is less than helpful on any assistance with configuring Exchange (any version) to work with their SMTP gateways. Really, I can't blame them too much because of the potential to hammering of their systems with large quantities of email from businesses using a "home"level of service.
In any event, here's how to configure Exchange 2007 with Edge services to send email through SBC Yahoo's email servers.
Configure the outbound Send Connector
- Logon to the server hosting the Hub Transport role
- Open the Exchange Management Console (EMC)
- Expand Microsoft Exchange\Organization Configuration\Hub Transport
- Click the Send Connectors tab
- Double-click your outbound SMTP connector to open its properties. Mine is named "EdgeSync - expta to the Internet"
- Click the Network tab
- Select "Route email through the following smart hosts" and click the Add button
- Select "Fully qualified domain name (FQDN)" and enter smtp.att.yahoo.com as the smart host. Click OK
- Select Basic Authentication (do not check Basic Authentication over TLS)
- Enter your SBC username (i.e., firstname.lastname@example.org) and SBC password. Click OK
Configure the Edge server to use port 587
- Yes, yes, I know that SBC's documentation says SSL port 469, but trust me, it's 587...
- On the Hub Transport server, open the Exchange Management Shell (EMS)
- Type Get-SendConnector and make note of the name of the send connector you just configured. Again, mine is "EdgeSync - expta to the Internet"
- Type Set-SendConnector "EdgeSync - expta to the Internet" -port 587 to change the port. Obviously, change the name in quotes to the name of your Send Connector.
- Type Start-EdgeSynchronization to force a sync with the Edge server
Force the Send Connetor to Retry
- Open EMC on the Edge server and click Toolbox
- Double-click Queue Viewer
- On the Queues tab, select the outbound SMTP queue and click the Retry action
Notes: TLS is not the same thing as SSL. TLS creates a secure connection between servers, while SSL creates a secure connection between a client and a server. TLS is capable of reverting back to SSL 3.0 if TLS doesn't work, but this is not an RFC requirement. At the time of this writing, Microsoft's implementation of TLS does not revert to TLS.
You should also register your external email address with SBC Yahoo's email system. This will ensure that email from your external account won't be NDR'd back to you when you send it. See http://help.yahoo.com/l/us/yahoo/mail/original/manage/sendfrom-07.html