After using the tool for 3 weeks, here are some thoughts that I would like to share.

I purchased the tool at first for the warmup email function, most of the email contents are non-sense but the stats look pretty good (100% landed in inbox), so I guess it's doing its job :)

For the campaign, stats are not detailed enough, and could not be read clearly unless download it as a file.

Customer service replies mostly in my evening/night, not sure what timezone they are in, I am in GMT+8.
But the customer service people are always nice and patient, and I always got the answer or the problem-solving way.

Since the app is pretty new and constantly evolving, I would still like to give it a five-star review, and look forward to improvement.