Emails not sending out. All mails sent out marked as "Host not reachable"

Emails not sending out. All mails sent out marked as "Host not reachable"

Hi,
So currently all of our emails sent out using zoho in browser are marked as in retry queue, with error details as "host not reachable". Of course this is not true - they are reachable, it is just that probably Zoho can not reach them. So when Zoho will be able to send out emails? It's a Black Friday make it working!!!