# MessageDeliveryTypeEnum

The delivery modes available for an email send definition.

## Values

| Name                        | Description                                                    |
| --------------------------- | -------------------------------------------------------------- |
| `Standard`                  | Indicates standard delivery of message.                        |
| `DelayedDeliveryByMTAQueue` | Indicates delivery delayed at the mail transfer agent servers. |
| `DelayedDeliveryByOMMQueue` | Indicates delivery delayed at the outbound message servers.    |

## Related Items

- [EmailSendDefinition](/docs/marketing/marketing-cloud/guide/emailsenddefinition.md)