Processed – Message has been processed and is ready to be delivered.

Delivered – Message has been successfully delivered.

Opened – Message has been opened by the recipient.

Clicked – Recipient has clicked on a link in the message.

Deferred – Receiving server temporarily rejected the message.

Dropped – Message not sent due to various reasons.

Bounced – Receiving server could not or would not accept the message.

Error – An error occurred while sending the message.