Hello,

I am getting an error in sending email ... the error follows

There has been an error trying to send the test email. The error is: The SMTP server requires a secure connection or the client was not authenticated. The server response was: 5.7.3 Client was not authenticated

thank you ...

Hello,

error was due to not checking anonymous in the authentication for smtp server, follows :

Run --> inetmgr --> Right click on default smtp server --> properties --> Access Tab --> Authentication --> 'Check' anonymous checkbox. 

After that i receive another error :

Exception message: Mailbox unavailable. The server response was: 5.7.1 Unable to relay for ............

do the following :

1. Open IIS.
2. Right click on "Default SMTP Virtual Server" and select "Properties".
    
3. Select the "Access" tab and click on the "Relay" button. This opens the Relay Restrictions window.
4. Select the "All except the list below" radio button.
5. Remove all items from the "list below".
6. Check the checkbox for "Allow all computers which successfully authenticate...".
7. Click OK.
8. Click on the "Authentication" button. This should open the Authentication window.
9. Make sure that only "Anonymous access" is checked.
10. Click OK.
11. Click OK again