If I go to settings, mail, folders and choose Inbox, the 'View in IMAP' checkbox is blank, If I check the box, shortly after, I get a message at the top of the screen 'Something went wrong' and if I go out and back to that screen, the checkbox is blank again. This means that I cannot use any email client except the Zoho app and Zoho web client. As I have over 1700 emails in  my inbox and it is still not possible to sort by sender (after over 4 years of many users trying to get this facility) it is almost impossible to manage my emails in any sensible manner.

I have actually just subscribed to the Lite plan thinking this might solve the problem, but it has made no difference.