I can open my emails, but they don't show as having been read.  I can't reply to any message I open.  I can compose a new message, but the contact list doesn't show when I click on "To".  I can fill in the "To" address by hand, but the message still refuses to send. 

Don't know if Zoho is the problem or the fact that Windows updated my computer this morning and it messed up my settings somehow.