try either:
"mailBody" => "Your requested information is \r\nUser name: [VisitorUserName]\r\nPassword: [VisitorPassword]\r\n If your password is blank please call\r\n 951-500-0478 or reply to this message and request a password reset",
or:
"mailBody" => "Your requested information is <br />User name: [VisitorUserName]<br />Password: [VisitorPassword]<br /> If your password is blank please call<br /> 951-500-0478 or reply to this message and request a password reset",