I've been slowly trying to warm up to this redesign over several months now. The biggest issue that still persists is that the tabs are WAY too visually subtle. They are practically invisible.

Tabs are an integral part of how I use Y!Mail (and pretty much the only reason why I didn't leave years ago since no one else has this feature). The tabs are so subtle that I often forget they are there. That defeats one of their key purposes: representing a pending task I need to resolve. I wish they were MUCH more visible.

P.S. I also feel like there is a lot of wasted vertical space. I feel like I'm constantly resizing my inbox panel and email panel (which are arranged on top of each other) because neither feel tall enough. I'm on the smallest spacing setting on a huge monitor and I still do this daily. I don't like the left-right orientation, but that might be the only way around this.

Both of these issues are about efficient productivity - I want my primary email to be a tool. If this were my junk email (which is gmail), I just wouldn't care as much, since I don't care as much about the contents of those emails.