This  new interface looks more modern, but I think it is LESS useful:

- Now the easy to read compose tabs that had labels at the top are GONE and replaced with tiny tabs that you have to mouse-hover over to identify.

- There is no longer a "compose to new window" option.

- The useful "Links" folder seems to no longer exist.

There is still functionality that does not exist that simply should exist in a full-fledged mail program:

- the ability to search in the "Drafts" folder still does not exist.  Really?!

- the long interval for calendar and contact updates between Outlook and web and/or gMail and web.

It appears that a lot of time, money and resources are spent on the new interface rather than on basic working infrastructure:

- Recent IMAP slowness problem

- Recent security/network breach.

Focus on the core!  You could be a gMail competitor if you focus on the core of what you have:

- "Streams"  really?  This seems only to work within Zoho.  This is NOT useful for 99% of the work the people do with the outside world...

Spend more time and resources on basic infrastructure and on improving your core functionality.