For those of you who need to use TLS for your mail server instead of SSL, here's some code from ChatGPT which you may find useful. I have not tried this myself, as I've never needed to use anything other than SSL:

I've been using Sendgrid with Microsoft Access for literally a decade, and I have never had to use TLS. I'm just using straight SMTP with an API key and port 465. However, a quick query of GPT gives me this:

In Microsoft Access VBA, when sending an email via SMTP using CDO, you need to set the appropriate configuration fields to enable TLS instead of SSL. TLS is often referred to as "STARTTLS" in SMTP configurations. Below is an example configuration for enabling TLS:

Code

Sub SendEmailWithTLS()
    Dim objMessage As Object
    Dim objConfig As Object
    Dim Fields As Object
    
    ' Create the email object
    Set objMessage = CreateObject("CDO.Message")
    Set objConfig = CreateObject("CDO.Configuration")
    Set Fields = objConfig.Fields
    
    ' Configure the SMTP server settings
    With Fields
        .Item("http://schemas.microsoft.com/cdo/configuration/smtpserver") = "smtp.example.com" ' Replace with your SMTP server
        .Item("http://schemas.microsoft.com/cdo/configuration/smtpserverport") = 587 ' Port for TLS
        .Item("http://schemas.microsoft.com/cdo/configuration/sendusing") = 2 ' cdoSendUsingPort
        .Item("http://schemas.microsoft.com/cdo/configuration/smtpauthenticate") = 1 ' Basic Authentication
        .Item("http://schemas.microsoft.com/cdo/configuration/sendusername") = "your_username" ' Your email username
        .Item("http://schemas.microsoft.com/cdo/configuration/sendpassword") = "your_password" ' Your email password
        .Item("http://schemas.microsoft.com/cdo/configuration/smtpusessl") = False ' Disable SSL
        .Item("http://schemas.microsoft.com/cdo/configuration/smtpusetls") = True ' Enable TLS
        .Update
    End With

    ' Configure the email message
    With objMessage
        Set .Configuration = objConfig
        .To = "[email protected]" ' Replace with recipient email
        .From = "[email protected]" ' Replace with sender email
        .Subject = "Test Email with TLS"
        .TextBody = "This is a test email sent using TLS."
        .Send
    End With
    
    ' Clean up
    Set objMessage = Nothing
    Set objConfig = Nothing
    Set Fields = Nothing
    
    MsgBox "Email sent successfully using TLS."
End Sub
Copy

Key Points:
1. TLS Port: Port `587` is typically used for TLS. Ensure your SMTP server supports this port.
2. Disable SSL: The `.Item("http://schemas.microsoft.com/cdo/configuration/smtpusessl")` property should be set to `False` for TLS.
3. Enable TLS: Use `.Item("http://schemas.microsoft.com/cdo/configuration/smtpusetls") = True` to explicitly enable TLS.

If your email provider does not specifically require `.smtpusetls`, using port `587` with `.smtpusessl = True` often negotiates TLS automatically. Ensure the server supports the protocol and authentication method you are trying to use.