Smtp failed to authenticate

Smtp failed to authenticate

I have setup a domain for my email account, and it is verified with mx record.

Here is my smtp settings:
  1. MAILER=smtp
  2. HOST=smtppro.zoho.com
  3. PORT=465
  4. USERNAME=xxxx@mydomain.com
  5. PASSWORD="xxxxxxxxxxxx"
  6. ENCRYPTION=ssl

But it keep failling with following message
  1.  Failed to authenticate on SMTP server with username "xxxx@mydomain.com" using 2 possible authenticators. Authenticator LOGIN returned Expected response code 235 but got code "535", with message "535 Authentication Failed
I tried with my primary email (which is super admin mail) but still failed. 
Do I need to create special username or password for the smtp settings?

The lack of documentations on this is so frustrating.