0 

Normal, successful completion. 

MTA_BADARGS

Received for one of two reasons: 

1. A NULL value was supplied for the dq_ctx call argument, an invalid dequeue context was supplied for dq_ctx.

2. A required argument to an item code was NULL.

MTA_NO

Unable to dequeue the message. This error can result from an attempt to enqueue a new message to a subset of recipients. 

MTA_NOSUCHITEM

An invalid item code was specified. 

MTA_ORDER

Call made out of sequence. The call was made either before the recipient list has been exhausted with mtaDequeueRecipientNext(), or after the message had been dequeued or deferred with mtaDequeueMessageFinish().

MTA_THREAD

The MTA SDK detected simultaneous use of the dequeue context by two different threads.