My email from zoho campaigns are falling under the promotions

My email from zoho campaigns are falling under the promotions

Hello!!

We were testing the Zoho campaigns for mass mailing. But most of the mail sent via Zoho are falling under the promotions section under the Gmail service. 

We don't want them to land under the promotions section, but rather under the inbox section directly. Please guide us on what should be done to achieve this. And what necessary changes need to be done for the same.