Our Zoho mail services is experiencing a network connectivity issues due to which users might notice an error " Problem sending email while doing an IO Operation", few users might also faces issues accessing our Zoho Mail service. 

Our engineering team is looking into it with very high priority to get things sorted out. We will keep you updated once it is fixed. 

We sincerely apologize for the inconvenience caused. Please bear with us till then. 

Your patience is highly appreciated!

Regards,

Zoho Mail Team.