Recipient email addresses are added to the Rejection Blacklist when one of the following events occurs:
- The recipient address bounces,
- The recipient address registers a spam complaint for an email sent to that address through the Mandrill account,
- The recipient address registers an unsubscribe for an email sent to that address through the Mandrill account, or
- The recipient address is manually added to the rejection blacklist.
Reject Reason: unsigned means that the message was sent from a domain that hasn't been fully configured for Mandrill.
You must add SPF and DKIM records and verify ownership of your sending domains before you can send email through your account. Mandrill will not send any email from unverified domains or domains without valid SPF and DKIM records.
While an email address is active on the Rejection Blacklist, emails to the address will be given a state of rejected and Mandrill won't try to deliver the emails. This helps prevent sending emails to an email address that is no longer valid, may be having temporary issues, or doesn't wish to receive emails from you.
After a rejection expires, if an email is sent to the address, Mandrill will attempt to deliver the message. Subsequent bounces, spam complaints, or unsubscribe attempts results in an address being added to the rejection list for longer periods of time.
Removing Rejection Blacklist entries
Rejected email addresses can be manually removed from the Rejection Blacklist one at a time for a small reputation hit. To remove an address from the rejection blacklist, go to the Rejection Blacklist page. Search for the email address you'd like to remove and click the remove link.
Accounts aren't charged for rejected emails and rejections do not affect your account reputation. Only the first bounce, spam complaint or unsubscribe is used to help calculate the account reputation.