Emails sent to spam for outlook/hotmail

Emails sent to spam for outlook/hotmail

Hello,

We've had this issue for a few days now, all our emails sent go straight to the spam folder for hotmail / outlook users, however they go into the mailbox for Gmail users.

We currently have 4 zohomail accounts, strangely only 1 of them can send emails to hotmail / outlook without the message going to spam, but we need to have them all work for hotmail.

Please help us resolve this issue,

Thanks.