PowerShell

1Send a test message

$password = ConvertTo-SecureString "pw_0000000000000000" -AsPlainText -Force
$credential = New-Object System.Management.Automation.PSCredential("mc_0000000000000000", $password)

Send-MailMessage -SmtpServer "smtp.mailclutch.com" -Port 587 -UseSsl `
  -Credential $credential `
  -From "staging@example.com" `
  -To "anyone@example.com" `
  -Subject "Sandbox check" `
  -Body "<h1>Hello from PowerShell</h1>" -BodyAsHtml

-UseSsl here means STARTTLS, which is what port 587 expects.

Watch it land

Open the sandbox and the message is there — rendered HTML, plain text, raw source, attachments, and the SPF, DKIM and DMARC verdicts. It updates live, so you can leave it open next to your terminal.

Nothing is ever delivered onward, whatever address you send to; claim the inbox with an account and it stays.

What usually goes wrong

• Send-MailMessage is deprecated

  Microsoft marks the cmdlet obsolete: it still ships and still works, but it is not maintained. For anything long-lived, use MailKit through Add-Type, or call a small script in another language.

• Windows PowerShell 5.1

  On 5.1 the default security protocol may exclude TLS 1.2. Run [Net.ServicePointManager]::SecurityProtocol = [Net.SecurityProtocolType]::Tls12 first.

Other stacks

The same four values in another dialect. Every guide below is filled in with the sandbox pair at the top of this page.