What does Mandrill status = "invalid" mean in Send Message API response

Question

Mandrill official documentation says that the status property in the response of Send Message API request is:

the sending status of the recipient - either "sent", "queued", "scheduled", "rejected", or "invalid"

Can't find anywhere what does invalid status indicate.

Any idea, referece ?

Answer 1

I had this happen because some of the properties in the JSON I posted had uppercase letters when the mandrill api was expecting lowercase.

I was using newtonsoft and solved it by adding JsonProperty attributes to my objects as described here: https://stackoverflow.com/a/34071205

Answer 2

One reason I have found is an invalid email address. For example having two dots in a domain like this: alice@example..com