Credential use in Send-MailMessage, can't get it to work programmatically

I have been working on this for 4 months and can't make it work except interactively, i.e., I have to enter my login name and pwd, manually.  I got this code from the forum from "jrv". Here's my code:

##This works perfectly but interactively! I even received and read the message.

$mailprops = @{
        ##User = 'me@mysite.com'
        ##Pword = ConvertTo-SecureString -String "xxxxxxxx" -AsPlainText -Force
        ##Cred = New-Object -TypeName System.Management.Automation.PSCredential -ArgumentList User, Pword

    From = 'me@verizon.net'
    To = 'you@verizon.net'
    Subject = 'PowerShell test of sending an email using your-site in e93.ps1'
    Body = 'PowerShell test of sending an email using your-site in e93.ps1'
    Attachments = 'D:\DOWNLOAD\xcopy.txt'
    SMTPServer = 'smtp.your-site.com'
    Port = '587'
    UseSSL = $true
    Credential = Get-Credential

    ##Credential = 'Cred'
    ##Credential = New-Object -TypeName System.Management.Automation.PSCredential -ArgumentList "them@verizon.net", "yyyyyyyyy"
    ##Credential = 'Cred'
    ##Credential = "www.gmail.com\mygmail"
    ##Credential = 'PSCredential'
}

Send-MailMessage @mailprops

------------------------------------------------
##This doesn't work from the PowerShell cmdline!

$mailprops = @{
    User = 'me@mysite.com'
    Pword = ConvertTo-SecureString -String "xxxxxxxxx" -AsPlainText -Force
    Cred = New-Object -TypeName System.Management.Automation.PSCredential -ArgumentList User, Pword
    From = 'me@verizon.net'
    To = 'you@verizon.net'
    Subject = 'PowerShell test of sending an email using your-site in e93.ps1'
    Body = 'PowerShell test of sending an email using your-site in e93.ps1'
    Attachments = 'D:\DOWNLOAD\xcopy.txt'
    SMTPServer = 'smtp.your-site.com'
    Port = '587'
    UseSSL = $true
    Credential = 'Cred'

        ##Credential = Get-Credential
        ##Credential = New-Object -TypeName System.Management.Automation.PSCredential -ArgumentList "them@verizon.net", "yyyyyyyyy"
    ##Credential = 'Cred'
    ##Credential = "www.gmail.com\mygmail"
    ##Credential = 'PSCredential'
}

Send-MailMessage @mailprops

------------------------------------------------
Here is the run and the errors:

PS D:\DOWNLOAD\PROGRAMS\POWERSHELL> .\e93

New-Object : Cannot find an overload for "PSCredential" and the argument count: "2".
At D:\DOWNLOAD\PROGRAMS\POWERSHELL\e93.ps1:11 char:12
+     Cred = New-Object -TypeName System.Management.Automation.PSCreden ...
+            ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : InvalidOperation: (:) [New-Object], MethodException
    + FullyQualifiedErrorId : ConstructorInvokedThrowException,Microsoft.PowerShell.Commands.NewObjectCommand

Send-MailMessage : Cannot validate argument on parameter 'To'. The argument is null or empty. Provide an argument that is not null or empty, and then try the command again.

At D:\DOWNLOAD\PROGRAMS\POWERSHELL\e93.ps1:28 char:18
+ Send-MailMessage @mailprops
+                  ~~~~~~~~~~
    + CategoryInfo          : InvalidData: (:) [Send-MailMessage], ParameterBindingValidationException
    + FullyQualifiedErrorId : ParameterArgumentValidationError,Microsoft.PowerShell.Commands.SendMailMessage
------------------------------------------------

This is driving me nuts. Just can't get it.  Any Help, that actually works, will be greatly appreciated!  
Thank you all Greatly in advance!
Crank