SMTP authentication

Hi!

I followed these instructions to enable SMTP for usage with gmail and thunderbird.

I am also using two factor authentication, so I created an application specific password.

I am using TLS (port 587) [STARTTLS in Thunderbird] and the username I am using for SMTP authentication is elias@cocoon-solutions.net.

Though, the authentication fails (gmail, which is more loquacious than thunderbird returns the following error: Authentication failed. Please check your username/password. Server returned error: "535 Authentication Failed code(535) ")

Which is the correct procedure for one to send mail through the zoho SMTP server?

Thank you very much,
Elias Polytarchos