Feature request: Track delivery failures at the adapter level

[nickjj]

Use case

Let's say you send out 10,000 e-mails advertising your latest shiny product. It would be extremely beneficial to know how many of those e-mails bounced for tracking purposes in third party tooling.

An e-mail can bounce in 2 ways, a soft and hard bounce. SendGrid has a nice article articulating the difference between the 2 https://sendgrid.com/blog/email-bounce-management/.

Feature

In the response of the sent message call, include if it was a success, soft bounce, hard bounce and perhaps other forms of failure that I haven't thought of but are common.