You've misspelled "$MailRecipient" as "$MailRecepient" in the value supplied for the "-To" parameter.
When you run into problems you don't understand, try adding Set-PSDebug -Strict
at the top of the script and then run the code. Or, better, use an IDE like VS Code (with the PowerShell Pro Tools extension), or the free version of Visual Studio for your development work. They include tools that will point out errors like that before you run the code.