All worked fine for few years but now when send email using Zoho account gmail error:  You're sending this from a different address or alias using the 'Send mail as' feature. The settings for your 'Send mail as' account are misconfigured or out of date. Check those settings and try resending.

When I try to setup  Send mail through your SMTP server  I am getting error:  Authentication failed. Please check your username/password.  Server returned error: "535 Authentication Failed , code: 535"

I checked user name and passwords and still the same error.