try:
    lead = db.session.query(Lead).filter(
        Lead.email_addr == mg_recipient
    ).first()

    if lead:

        email = lead.email
        lead_id = lead.id
        event = form_data['event']

        # set the delivered flags in the database
        lead.followup_email_delivered = 1
        lead.followup_email_status = event
        lead.webhook_last_updated = datetime.now()
        db.session.commit()

        # return a successful response
        return jsonify({
            "l_id": lead_id,
            "email": email,
            "event": event,
            "status": 'success'}), 202

    # return 404: no email for recipient email address
    else:
        resp = {"Error": "Unable to resolve the recipient email address..."}
        data = json.dumps(resp)
        return Response(data, status=404, mimetype='application/json')

# database exception
except exc.SQLAlchemyError as db_err:
    resp = {"Database Error": str(db_err)}
    data = json.dumps(resp)
    return Response(data, status=500, mimetype='application/json')