Based on your company's focus on natural and organic pet products and your goals of increasing engagement and sales while minimizing unsubscribes, here is my recommendation for optimizing your email frequency:
By segmenting your list based on engagement levels, increasing your newsletter cadence, and introducing targeted emails for VIPs and key customer actions, you can deliver more relevant, timely content to your subscribers. Combined with a regular testing and optimization process, these frequency adjustments should help improve your email performance against your goals. The key is striking the right balance of value and promotion for each segment while staying responsive to subscriber preferences.