Emails not going to Clients - Zoho Desk

Emails not going to Clients - Zoho Desk

Hi,

We are using Zoho Desk to provide support from our department to all company staff. We have configured our email in Zoho for sending notifications to all clients for ticket creation, closing, or any other replies etc. it was working fine but from last few days, our clients are not receiving any emails form our Zoho Desk. We need urgent support on this issue.