| Instance Variable | mbox | See __init__. | 
| Instance Variable | defer | A deferred which fires when the task has completed. (type: Deferredwhich successfully returnsNone) | 
| Instance Variable | opencall | A scheduled call to prodProducer. (type:IDelayedCallprovider orNone) | 
| Instance Variable | msg | The message to add. (type: file-like object) | 
| Instance Variable | tmpname | The pathname of the temporary file holding the message while it is being 
transferred. (type: bytes) | 
| Instance Variable | fh | The new maildir file. (type: file) | 
| Instance Variable | filesender | A file sender which sends the message. (type: FileSender) | 
| Instance Variable | myproducer | The registered producer. (type: IProducer) | 
| Instance Variable | streaming | Indicates whether the registered producer provides a streaming interface. (type: bool) | 
| Method | __init__ |  | 
| Method | startUp | Start transferring the message to the mailbox. | 
| Method | registerProducer | Register a producer and start asking it for data if it is 
non-streaming. | 
| Method | prodProducer | Repeatedly prod a non-streaming producer to produce data. | 
| Method | unregisterProducer | Finish transferring the message to the mailbox. | 
| Method | write | Write data to the maildir file. | 
| Method | fail | Fire the deferred to indicate the task completed with a failure. | 
| Method | moveFileToNew | Place the message in the new/ directory, add it to the mailbox 
and fire the deferred to indicate that the task has completed 
successfully. | 
| Method | createTempFile | Create a temporary file to hold the message as it is being 
transferred. |