Based on the users' reviews of the Mail Stack app, here are three cons and pros: **Cons:** 1. "Customer support is unresponsive to concerns, making it difficult to resolve issues." (15 words) 2. "Occasional server downtime and maintenance interruptions affect email functionality." (15 words) 3. "Limited customization options for email settings, which can be frustrating for some users." (15 words) **Pros:** 1. "User-friendly interface makes it easy to set up and use the email client." (15 words) 2. "Effective spam filter keeps unwanted emails from cluttering the inbox." (15 words) 3. "Good customer ratings and positive reviews from satisfied users, building trust." (15 words) Please note that these conclusions are based on the available user reviews at the time and may change as more reviews are added.