How to identify mandrill webhook

Question

I have a Rails 4 application which sends emails using Mandrill. I am trying to detect weather a mail was opened or bounced, so I am using webhooks for this. I successfully receive the webhooks, but I can't tell which of them identify a particular email from my database.

I've tried using this

  def send_message(email)

    mail( from: ...,
          to: ...,
          subject: ...)

    headers["X-MC-AutoHtml"] = "true"
    headers["X-MC-Track"] = "opens"
    headers['X-MC-MergeVars'] = { "id" => some_id }.to_json
  end

but I'm not sure if I'm supposed to receive the X-MC-MergeVars back ( this is what I've understand from the docs)

Unfortunately, it's not working.

Do you have any ideas or an alternative solution? Thanks

Answer 1

I've figured it out by myself.

This is the line that needs to be there

headers['X-MC-Metadata'] = { "user_id" => user.id}.to_json

Here are the further details: http://help.mandrill.com/entries/21786413-Using-Custom-Message-Metadata

Hope it helps someone since it cost me several hours.