Send Email in SharePoint Using JQuery REST API

In SharePoint 2013 on-Premise or Office 365 we can send email using REST API using SP.Utilities.Utility.SendEmail

* Note: The recipient is limited to a valid SharePoint user.it will not work for external user.

             to send email to external user we can use SharePoint 2010 workflow email activity

function sendEmail(from, to, body, subject) {

var siteurl = _spPageContextInfo.webServerRelativeUrl;

var urlTemplate = siteurl + "/_api/SP.Utilities.Utility.SendEmail";

$.ajax({

   contentType: 'application/json',

   url: urlTemplate,

   type: "POST",

   data: JSON.stringify({

        

     'properties': {

           '__metadata': { 'type': 'SP.Utilities.EmailProperties' },

           'From': from,

           'To': { 'results': [to] },

           'Body': body,

           'Subject': subject

       }

   }

 ),

   headers: {

       "Accept": "application/json;odata=verbose",

       "content-type": "application/json;odata=verbose",

       "X-RequestDigest": $("#__REQUESTDIGEST").val()

   },

   success: function (data) {

      alert("Eposten ble sendt");

   },

   error: function (err) {

       alert(err.responseText);

       debugger;

   }

});

}