All of the mail views in Zoho Mail are like a late 1990s throwback - especially when you have Vertical Preview mode, and have opened an email, the middle pane is basically useless. Trident does such a better job in terms of layout of contact, subject, and preview, as well as date/time, so that you can actually see it all and not have massive wasted space around the date/time.

Compare the same email below, viewed in Zoho Mail and then Trident - it's not even comparable. It shouldn't be too difficult to replicate that kind of a mail view in Zoho Mail, and would make the app look 1000% more modern.