Some background:

When I a run a campaign, I check the report on who's opened it. I have created a custom field in Zoho Campaigns called "Campaign Email Opened", and I run a mass update on all those who have opened the email to update this field.

How can I sync this field into a custom field in Zoho CRM Contacts? I've tried making the field text, checkbox & pick list with a required field in Zoho CRM, but when I try to map these in the Campaigns to CRM sync it doesn't let me.

Any ideas?

Thanks