Return message id from v3 send API

[philbooth]

I need to access the message id returned by the v3 send API, but couldn't see a way to do it. Am I missing something?

To get something working in the meantime, I ended up making a branch that returns it instead of the response status, getting the value out of the X-Message-Id header. Is there some version of that change that would be worth me tidying up and opening as a PR?

[gsquire]

Thanks for opening this issue. I have debated returning the reqwest::Resposne type and just re-exporting it. This would give the user access to the headers and other parts of the response. Would this suffice? If so, I will make a PR soon.

[philbooth]

Would this suffice?

Yep, works for me!

[gsquire]

This was updated in version 0.7.0.