Hey @Piny - when you invoke an agent via email, the body and sender are all passed into the first message to the agent:
From: {emailData.from}
Cc: {emailData.Cc} (if present)
To: {other recipients} (if present, excluding the agent email)
Subject: {emailData.subject}
Message-Id: {emailData['Message-Id']}
{emailData['stripped-text']}
In your agent instructions you could reference these things, and the agent will have them in context. Here's an example of me emailing an agent and asking what it was invoked with:
Let me know if you have additional questions!