I've been experiencing issues with the app's email syncing functionality. Despite setting it to send a certain percentage of my emails daily (20%), the emails remain queued and unsent for several days. For example, if I set it to send 100 emails with a 20% daily increase, the app won't send any emails initially. Then, after a few days, it suddenly syncs and sends all accumulated emails at once. This leads to a burst of over 200 emails being sent in a single day, which is not what I intended.

Additionally, customer service is non-existent. It's been five days since I emailed them, and I have yet to receive a reply.