Enhance n8n Workflow with Email & Slack Integration

I’m looking for an n8n automation expert to optimize and extend my current workflow.

Right now, I have a workflow that:
• Captures leads from Systeme.io
• Stores them in Supabase with a Retell client ID
• Triggers Retell AI calls
• Generates a summary of the call
• Sends a notification with the summary into Slack

What I need:
• Instead of posting all summaries in one Slack workspace, I need the system to:
1. Send an individual email with the call summary to each collaborator
2. Send the same summary into a separate Slack workspace for each collaborator (so that information is not shared across the whole team)

Requirements:
• Strong experience with n8n workflows
• Familiarity with Slack API, Supabase, and email integrations
• Experience with data privacy & secure automations (important to avoid cross-sharing of sensitive client data)

Deliverables:
• Adjusted n8n workflow with the above logic
• Documentation on how the workflow was built so I can maintain it
• Basic testing to ensure no cross-sharing happens between collaborators