Sending gmail attachment using api failed

Question

I\'m trying create a draft (or send a message) with attachment to gmail using its API. I\'ve read some answers and tried to built the request according to what I\'ve read he

Answer 1

OK, so if you're using the /upload media feature (works for all messages irregardless of size) then for example it should be something like the following (and looks like i was a bit mistaken):

POST https://www.googleapis.com/upload/gmail/v1/users/me/messages/send
Content-Type: multipart/related; boundary=foo_bar_baz

then your POST body should be something like the following (not encoded, etc):

--foo_bar_baz
Content-Type: application/json; charset=UTF-8

{
}

--foo_bar_baz
Content-Type: message/rfc822
MIME-Version: 1.0
to: receiver@gmail.com
from: sender@gmail.com
subject: Testing Subject

--foo_bar_baz
Content-Type: text/plain; charset="UTF-8"
MIME-Version: 1.0
Content-Transfer-Encoding: 7bit

This is the testing text

--foo_bar_baz

Content-Type: image/jpeg
MIME-Version: 1.0
Content-Transfer-Encoding: base64
Content-Disposition: attachment; filename="test.jpg"




--foo_bar_baz--

So things to note are that it's actually "multipart/related" and that has a application/json (for some requests you can add parameters there) part as well as a message/rfc822 part that contains the entire email.

It's not easy for sure--libraries definitely make it less painful if you can use them!