Due to the issue with "DYN" DNS provider since 11 am UTC, our users might be unable to access zoho.com and other Zoho urls like mail.zoho.com, crm.zoho.com, etc. It was resolved as of 13:20 UTC, however it has resurfaced an hour ago. Our network infrastructure team is working on alternative backup plans to solve this issue. We will keep you informed once that is complete. Apologies for the inconvenience caused.
On a related note, many major websites like Twitter, Paypal, Basecamp, Zendesk, etc. are also affected due to this.
We would like to confirm that this issue has been addressed and you will start receiving incoming emails and also you will be able to access Zoho websites.
There was an DDOS attack on the servers of Dyn (where Zoho's name server was pointing) due to which most of the websites were facing intermittent access. As we have moved our name server out of DYN, you should be able to access our mail service and other Zoho Services.
During this transition of name server, your incoming emails would have been bounced back to senders. However, based on subsequent retry mechanism of the sending server, your emails will be delivered with a delay.
Note: If you have your domain with Dyn, you still not be able to receive emails as the issue with Dyn still exists.