Gmail API send message without using Base64 encode

Question

I am using this interface: https://developers.google.com/gmail/api/v1/reference/users/messages/send#examples

I was testing API request from the form on the website. It requires raw Base64 encoded string such as:

TUlNRS1WZXJzaW9uOiAxLjANClJlY2VpdmVkOiBieSAxMC4xOTQuNjguMjI3IHdpdGggSFRUUDsgV2VkLCAyNCBBdWcgMjAxNiAwMjo1OToxNyAtMDcwMCAoUERUKQ0KRGF0ZTogV2VkLCAyNCBBdWcgMjAxNiAxMTo1OToxNyArMDIwMA0KRGVsaXZlcmVkLVRvOiBrcnVub0B1bGl4dHJhdmVsLmNvbQ0KTWVzc2FnZS1JRDogPENBSzB5QmZZeEgwS1dGbng2TzNfZ3ZNRkxtVlB5RVY9NjdnQW5qRWdPaHIzSGZOTkJCUUBtYWlsLmdtYWlsLmNvbT4NClN1YmplY3Q6IFRoaXMgaXMgYSBzdWJqZWN0DQpGcm9tOiBLcnVub3NsYXYgVUxJWFRyYXZlbCA8a3J1bm9AdWxpeHRyYXZlbC5jb20-DQpUbzogS3J1bm9zbGF2IEJhbm92YWMgPGt1bm9rZGV2QGdtYWlsLmNvbT4NCkNvbnRlbnQtVHlwZTogbXVsdGlwYXJ0L2FsdGVybmF0aXZlOyBib3VuZGFyeT0wNDdkN2JhZTQ5NjRhMmQ3MzAwNTNhY2U1NWUxDQoNCi0tMDQ3ZDdiYWU0OTY0YTJkNzMwMDUzYWNlNTVlMQ0KQ29udGVudC1UeXBlOiB0ZXh0L3BsYWluOyBjaGFyc2V0PVVURi04DQoNClRoaXMgaXMgYSBib2R5DQoNCi0tMDQ3ZDdiYWU0OTY0YTJkNzMwMDUzYWNlNTVlMQ0KQ29udGVudC1UeXBlOiB0ZXh0L2h0bWw7IGNoYXJzZXQ9VVRGLTgNCg0KPGRpdiBkaXI9Imx0ciI-VGhpcyBpcyBhIGJvZHk8YnI-PC9kaXY-DQoNCi0tMDQ3ZDdiYWU0OTY0YTJkNzMwMDUzYWNlNTVlMS0t

How do I instead use basic parameters (such as subject, sender, reciver, message body) to send mail?

Answer 1

You first build the message with headers likeFrom and Subject as you mentioned, but you have to encode the message before sending it. There is no way around that.

The following is an example in JavaScript, with the use of JQuery:

// Base64-encode the mail and make it URL-safe 
// (replace all "+" with "-" and all "/" with "_")
var encodedMessage = btoa([
  "From: [email protected]\r\n",
  "To: [email protected]\r\n",
  "Subject: Subject of the message\r\n\r\n",

  "This is the text of the message"
].join("")).replace(/\+/g, '-').replace(/\//g, '_');

$.ajax({
  method: "POST",
  url: "https://www.googleapis.com/gmail/v1/users/me/messages/send?access_token={access_token}",
  contentType: "application/json",
  data: JSON.stringify({           
    raw: encodedMessage
  })
});