All my Mass mails and Campaigns sent from ZOHO are going to SPAM

All my Mass mails and Campaigns sent from ZOHO are going to SPAM

We are sending mail using the following :

1. Direct Email using ZOHO.... these are going but mostly to SPAM
2. Marketing Automation - these are either not going or going to SPAM
3. Campaigns - These are also either not going or going after a long time and that too to SPAM

This is very urgent

Please resolve