IIS SMTP - The server response was: 5.7.1 Unable to relay for outgoing address, Still not working

I have read Mailbox unavailable. The server response was: 5.7.1 Unable to relay for abc@xyz.com and all of the answers. I have added my IP address via

IIS-->Default开发者_StackOverflow中文版 SMTP Virtual Server-->Properties-->Access-->Relay restrictions just add or exclude >the IPs you care about, should resolve the issue.

but it still gives me the error as above. What am I doing wrong?

I'm using Windows Sever 2003 R2 and IIS6.

I was able to fix this in my case by:

1. Go to Administrative Tools -> IIS 6.0 Manager
2. Right click "SMTP Virtual Server" then Click Properties
3. Select Access tab
4. Click "Relay..." in Relay Restrictions
5. Select "Only the list below"
6. Add 127.0.0.1 and my server IP to the list
7. Check Allow all computers which successfully authenticate to relay, regardless of the list above
8. Click "OK"