I’ve just published an article on deadlettering on “Deadlettering in Azure AppFabric Service Bus Brokered Messaging”. It looks at how deadlettering can be used to handle poison messages, and messages that do not meet business rules.
The article will be included in the next release of “The Developer’s Guide to AppFabric”, a free e-book on Azure AppFabric development. The latest edition of the e-book is available for download here.