pop gmail not working

pop gmail not working

Hello
I wonder if you can help me.  My email is handled by gmail and I have integrated it into Zoho CRM.  I followed all the steps in your manual and for a couple of weeks it worked.  but now it has stopped.  My emails are arriving and sending in gmail without a problem but none of them are attaching to my client contact records.
I have checked that my pop is enabled and have even bought additional zoho mail capacity. but no joy.  Driving me mad!