The Send-MailMessage cmdlet sends an email message from within PowerShell. You must specify a Simple Mail Transfer Protocol (SMTP) server or the Send-MailMessage command fails. Use the SmtpServer parameter or set the $PSEmailServer variable to a valid SMTP server. The value assigned to $PSEmailServer is the default SMTP setting for PowerShell. For more information, see about_Preference_Variables.  Warning The Send-MailMessage cmdlet is obsolete. This cmdlet does not guarantee secure connections to SMTP servers. While there is no immediate replacement available in PowerShell, we recommend you do not use Send-MailMessage. For more information, see Platform Compatibility note DE0005.