Function extract_mx_content 

pub fn extract_mx_content(
    message_data: &Value,
    field_name: &str,
    message_payload: &Value,
) -> Result<String>

Extract MX content from a message field

This function handles various formats of MX message content:

• Direct string values
• Objects with mx_message field (from generate_mx output)
• Payload field

Arguments

• message_data - The message data object
• field_name - The field name to extract from
• message_payload - The message payload (if field_name is “payload”)

Returns

• Ok(content) - The extracted MX message content
• Err(error) - If content cannot be extracted