Zoho mail bug? Downloaded emails in outlook are being downloaded again and again

Zoho mail bug? Downloaded emails in outlook are being downloaded again and again

I’ve been using zoho mail for over a year now on outlook.  I switched from windows to mac a few months ago and I must say the Zoho/outlook 2011 experience isn’t as smooth as with windows.  
The latest problem is that all my emails which have already been downloaded are showing up in queue - over 2200 of them.  Please see image. I have not changed any settings on zoho mail, nor in my outlook.  So this is obviously a bug in zoho email.  Let me know what I can do as Zoho mail does not have the pop3 feature which enables “dowload emails which arrive from now on” as in gmail, so I am now forced to use zoho mail online rather than outlook until this is sorted out. 
This has happened a couple of times before but its autocorrected itself (though I was forced to stop using outlook and had to check every few hours) but this is getting rather frequent.  Attached are some screenshots - please see the rounded areas and also my settings.