If true, a message that has already been seen (duplicate) is immediately treated as processed and will not be reservable again. This effectively disables retries and provides at‑most‑once delivery semantics. If false (the default), an orphaned reservation (where IsProcessed is still false) can be reclaimed atomically, allowing MassTransit to retry the message and expecting an idempotent handler.

Declaration

public bool MarkProcessedAfterFirstAttempt { get; set; }

Property Value

Type	Description
bool