Hi @egeersoz, thanks for opening this issue and for the patience! I'm taking over maintenance of Bamboo and trying to go through all the issues.

Having the ability to set content_disposition to %Bamboo.Attachment{} makes sense to me and then mapping that to the disposition attribute in the SendgridAdapter.

If this is still of interest to you, I'd be happy to review a PR. Otherwise, I'll try to get to this when I have some time.

Any chance we can merge @sreecodeslayer PR? It looks good to me.

HI @germsvel and @sreecodeslayer 👋

I've had to solve this problem for the use case of inline images. My approach was to do something a bit more general and to simply allow the user to provide arbitrary header overrides to the adapter. I see @sreecodeslayer that you've implemented a specific solution for your use case, but I'd like you both to consider this one which solves both our problems.

#631

Please let me know what you think. Also note, that for inlined content (at least for images) its important to reorganize the multipart arrangement in the adapter. In particular it needs to be arrange liked this:

start multipart/mixed
  start multipart/related
    start multipart/alternative
      <text and html parts>
    end multipart/alternative
    <inline parts>
  end multipart/related
  <attachment parts>
end multipart/mixed

I've made this change for the bamboo_ses adapter here: kalys/bamboo_ses#43

From some reason bamboo_ses has a duplicated renderer from the :mail module. The PR for that is here: DockYard/elixir-mail#137

Ran into a problem that I think this issue would solve.

When using the SendgridAdapter, it's not possible (maybe incorrect?) to refer to the inlined images using cid:. This is because the Content-Id header is not set on attachments for SendgridAdapter.

Is there an alternative?