Unable to connect SMTP server:smtp.zoho.com Reason:Authentication failed:535 Authentication Failed

Unable to connect SMTP server:smtp.zoho.com Reason:Authentication failed:535 Authentication Failed

HI, I just started a new account and found I can't send email, or receive. What's wrong with this? I found I even can't post the issue here. Hope you guys can respond quickly. 

Cheers,
August