Forward mail using gmail API

I don't see any specific forward operation...

You'll have to:

1. get the message,
2. add your extra content to the top of the original message and
3. change the to address, then
4. send it.

Not much help to you but take note of the Threads.

Watch out while doing this procedure !

I used the answer of Jhon Mee to forward all emails from a user to an other one. If you just change the "To:" it will continue to send the emails to everyone in "Cc:" and "Bcc:"

Here is the procedure:

1. Retreive the email in raw format
2. Decode the email from base64
3. Replace the line "To:" with the email you want to forward to
4. Remove the lines "CC:" and "Bcc:"
5. Send it