Failure to connect to Zoho SMTP when trying to send an email using VBA

I am trying to use VBA from Excel to send an email.
I think I have all the correct settings, but I get the error:

"The server rejected the sender address. The server response was: -ERR USER NOT AUTHENTICATED"

This tells me that a connection WAS made to the server and that the SMTP server decided not to allow that user in.
The username and password I have used work when I log into zoho, and I have checked and re-checked the code to make sure I did not make username or pw mistake.

This a copy of the relevant code is: (I have starred out my pw and username, but they are correct)

    Set CDO_Config = CreateObject("CDO.Configuration")
    CDO_Config.Load -1
    Set SMTP_Config = CDO_Config.Fields
    With SMTP_Config
        .Item("http://schemas.microsoft.com/cdo/configuration/sendusing") = 2
        .Item("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate") = cdoBasic
        .Item("http://schemas.microsoft.com/cdo/configuration/sendusername") = "*********@************.com"
        .Item("http://schemas.microsoft.com/cdo/configuration/sendpassword") = "**************"
        .Item("http://schemas.microsoft.com/cdo/configuration/smtpusessl") = True
        'please put your server name below
        .Item("http://schemas.microsoft.com/cdo/configuration/smtpserver") = "smtp.zoho.com"
        .Item("http://schemas.microsoft.com/cdo/configuration/smtpserverport") = 465
        .Update
    End With
    With CDO_Mail_Object
        Set .Configuration = CDO_Config
    End With

Any ideas why it does not work?

-MOE-