refactor: Implement CrewAI Flow for email processing

- Add EmailState model for Flow state management
- Create EmailProcessingFlow class with event-based automation
- Update tools and crews for Flow integration
- Add comprehensive Flow tests
- Implement error handling and state tracking
- Add mock implementations for testing

This implementation uses CrewAI Flow features to create an event-based
email processing system that can analyze emails, research senders,
and generate appropriate responses using specialized AI crews.

Co-Authored-By: Joe Moura <joao@crewai.com>

tests/test_crewai_components.py

@@ -0,0 +1,64 @@
+from crewai import Agent, Task, Crew, Process
+from typing import List
+import json
+from pydantic import BaseModel
+import os
+
+# Define output models
+class EmailAnalysis(BaseModel):
+    needs_response: bool
+    priority: str
+    context: str
+
+# Sample email data for testing
+SAMPLE_EMAIL = {
+    "subject": "Meeting Follow-up",
+    "body": "Thanks for the great discussion yesterday. Looking forward to next steps.",
+    "sender": "john@example.com"
+}
+
+# Test Agent Creation
+researcher = Agent(
+    role="Email Researcher",
+    goal="Analyze email content and gather relevant context",
+    backstory="Expert at analyzing communication patterns and gathering contextual information",
+    verbose=True,
+    allow_delegation=True
+)
+
+# Test Task Creation
+analysis_task = Task(
+    description=f"Analyze this email content and determine if it requires a response: {json.dumps(SAMPLE_EMAIL)}",
+    agent=researcher,
+    expected_output="Detailed analysis of email content and response requirement",
+    output_json=EmailAnalysis
+)
+
+# Test Crew Creation with Sequential Process
+crew = Crew(
+    agents=[researcher],
+    tasks=[analysis_task],
+    process=Process.sequential,
+    verbose=True
+)
+
+# Test execution with error handling
+if __name__ == "__main__":
+    try:
+        # Ensure we have an API key
+        if not os.getenv("OPENAI_API_KEY"):
+            print("Please set OPENAI_API_KEY environment variable")
+            exit(1)
+
+        result = crew.kickoff()
+        print("Execution Results:", result)
+
+        # Access structured output
+        if hasattr(result, "output") and result.output:
+            analysis = EmailAnalysis.parse_raw(result.output)
+            print("\nStructured Analysis:")
+            print(f"Needs Response: {analysis.needs_response}")
+            print(f"Priority: {analysis.priority}")
+            print(f"Context: {analysis.context}")
+    except Exception as e:
+        print(f"Error during execution: {str(e)}")