We use the integration between Zoho Desk and Zoho CRM. According to this integration the contacts from Zoho Desk clients sync to Zoho CRM. 

Unfortunately the integration has one major issue: Contacts created from Desk in CRM have no Lead Source. This is a major issue because:

1) Spam contacts are also created in CRM, and CRM is now full of this shitty emails.

2) Those contacts sync with Zoho Campaings and they (a) bounce, and (b) we pay for them because the tarif plans of Zoho Campaings depends on the number of contacts.

I am writing to your support for more than half a year, and you just cannot fill the files Lead Source with "Zoho Desk" for the Desk contacts.

Please fix it asap and refund our extra spendings for Zoho Campaigns.