SMTP Error (435): Authentication failed.

[xbot]

please help guys.
I am new at hosting.
I get SMTP Error (435): Authentication failed. when trying to send emails using roundcube, also get an error using squerell mail.
same error using apps like turbo mailer.
don't know what the problem is.
how do I fix this.
thanks in advance.

 

[Petertjuh360]

Run:

cd /usr/local/directadmin/custombuild
./build update
./build exim
./build roundcube

And try again