diff --git a/EnvelopeGenerator.Application/DependencyInjection.cs b/EnvelopeGenerator.Application/DependencyInjection.cs
index 35a49835..ba534ae2 100644
--- a/EnvelopeGenerator.Application/DependencyInjection.cs
+++ b/EnvelopeGenerator.Application/DependencyInjection.cs
@@ -61,13 +61,16 @@ public static class DependencyInjection
             cfg.RegisterServicesFromAssembly(Assembly.GetExecutingAssembly());
             
             // Register SignCommand pipeline behaviors in execution order
-            // 1. AnnotationBehavior - Saves annotations (executes first)
+            // 0. EnvelopeReceiverResolutionBehavior - Resolves EnvelopeReceiver from query parameters (executes FIRST)
+            cfg.AddBehavior<IPipelineBehavior<SignCommand, Unit>, EnvelopeReceiverResolutionBehavior>();
+            
+            // 1. AnnotationBehavior - Saves annotations (executes second)
             cfg.AddBehavior<IPipelineBehavior<SignCommand, Unit>, AnnotationBehavior>();
             
-            // 2. DocStatusBehavior - Creates document status (executes second)
+            // 2. DocStatusBehavior - Creates document status (executes third)
             cfg.AddBehavior<IPipelineBehavior<SignCommand, Unit>, DocStatusBehavior>();
 
-            // 3. HistoryBehavior - Records history (executes third)
+            // 3. HistoryBehavior - Records history (executes fourth)
             cfg.AddBehavior<IPipelineBehavior<SignCommand, Unit>, HistoryBehavior>();
             
             // 4. SendSignedMailBehavior - Sends notification email (executes LAST, only if all previous succeed)