| Classification | 
      
          | ok | Message has been successfully delivered. | 
      
          | bad-content | Message has been identified by the receiving email server as SPAM. Determined by the content or sender of the message. | 
      
          | bad-relay | Recipient mail server temporary error, misconfiguration or the server is undergoing maintenance. | 
      
          | blocked | Delivery has been denied from Smaily (or any service). | 
      
          | client-error | Smaily misconfiguration or error denying message delivery. | 
      
          | expired | Message delivery has taken more than the maximum amount (2 days) of time. | 
      
          | mailbox-disabled | Message recipient's mailbox is disabled or inactive. | 
      
          | mailbox-full | Message recipient's mailbox is full. | 
      
          | mailbox-unknown | Message recipient's mailbox does not exist. | 
      
          | rate-limit | Hourly/daily sending limits exceeded. | 
      
          | signature-error | Incorrectly configured SPF or invalid DKIM signature. | 
      
          | temp-error | Temporary delivery error. | 
      
          | unknown | Message status unknown. |