1. Huge email deliverability issues. Quite a few emails just get lost somehow. Just today, someone forwarded a book and hours later I still haven't received it.

2. Terrible, Inconsistent UI.

3. Push notifications are broken and Their apps are broken. I dont get notifications in clients configured with IMAP and their apps also dont send notifications. I have to manually refresh in both cases.

4. Relatively minor issue but I am against Zoho's founder's political alignment, and that is putting this issue mildly.