Can't send email through Powershell - powershell

Question

I have been trying to use this script as a simple boolean that checks for a file, and sends a success email, or a failure email. But I cannot for the life of me figure out why it doesn't work.
Any ideas?
$SMTPServer = "smtp.gmail.com"
$SMTPPort = "587"
$Username = "xxxx#xxxxx.com"
$Password = "xxxxxxx"
$to = "xxx#xxxxx.net"
if ( ([System.Io.fileinfo]'E:\GD Backup Folder\backup\Backup_*.zip').LastWriteTime.Date -ne [datetime]::Today ) {
$message = New-Object System.Net.Mail.MailMessage
$message.subject = "Backup Successful"
$message.body = "Backup was successful."
$message.to.add($to)
$message.from = $username
$smtp = New-Object System.Net.Mail.SmtpClient($SMTPServer, $SMTPPort);
$smtp.EnableSSL = $true
$smtp.Credentials = New-Object System.Net.NetworkCredential($Username, $Password);
$smtp.send($message)
write-host "Mail Sent"
}else{
$message = New-Object System.Net.Mail.MailMessage
$message.subject = "Backup Unsuccessful"
$message.body = "Backup was NOT Successful - File Not Found"
$message.to.add($to)
$message.from = $username
$smtp = New-Object System.Net.Mail.SmtpClient($SMTPServer, $SMTPPort);
$smtp.EnableSSL = $true
$smtp.Credentials = New-Object System.Net.NetworkCredential($Username, $Password);
$smtp.send($message)
write-host "Mail Sent"
}

Answer 1

Send email with attachment using powershell -
$EmailTo = "udit043.ur#gmail.com" // abc#domain.com
$EmailFrom = "udit821#gmail.com" //xyz#gmail.com
$Subject = "zx" //subject
$Body = "Test Body" //body of message
$SMTPServer = "smtp.gmail.com"
$filenameAndPath = "G:\abc.jpg" //attachment
$SMTPMessage = New-Object System.Net.Mail.MailMessage($EmailFrom,$EmailTo,$Subject,$Body)
$attachment = New-Object System.Net.Mail.Attachment($filenameAndPath)
$SMTPMessage.Attachments.Add($attachment)
$SMTPClient = New-Object Net.Mail.SmtpClient($SmtpServer, 587)
$SMTPClient.EnableSsl = $true
$SMTPClient.Credentials = New-Object System.Net.NetworkCredential("udit821#gmail.com", "xxxxxxxx"); // xxxxxx-password
$SMTPClient.Send($SMTPMessage)