How are rejected emails handled? When is an email address considered to be inactive?
We will try to send a message 6 times—one initial send and five retries over a 48 hour period. If a mail server reports that an address is permanently non-deliverable, we will only attempt to deliver to it once for that mailing. This kind of bounce is a permanent failure. A message that is undeliverable for other reasons (e.g., mailbox is full or mail server does not respond) is a transient failure. If an address is undeliverable for the initial send and all the retries, it is considered to have bounced once.
