Hi
Jorge Ramirez Duran Thanks for reaching out. You can view the details for deadletter meaages using ServiceBus explorer
Latest Source Binaries
https://github.com/paolosalvatori/ServiceBusExplorer
Download at this link. It is standalone so no installation is required, just unzip and run it.
https://github.com/paolosalvatori/ServiceBusExplorer/releases
Step 1: Go to the corresponding namespace in the Azure Portal. Click on Settings-> Shared Access Policies and double click on RootManageSharedAccessKey. Copy the Connection string-primary key and keep this value handy.
NOTE: You have to use a connection string with Manage Claims with Service Bus Explorer.
Step 2: Open ServiceBus Explorer go to file -> Connect --> In the Service Bus Namespace dropdown menu, choose "Enter connection string" and add your Connection string-primary key from step 1 and click on "OK."
Step 3: Once you have successfully connected to your Service Bus namespace, select one of your queues and the middle value shows the no of dead letter messages in your queue as shown below
Click the "Deadletter" button at the bottom
Select "Peek" to peek some messages from the deadletter and click "Ok" You can then review the deadletter reason, Enqueued time for each individual message as shown below, you can also download the message details by clicking "save selected messages".
Hope this helps!
please let me know incase of further queries, I would be glad to help you.
Please do "Accept the answer” and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.