title: error with linux-based mailserver
body: <p>i got the following problem with my myserver based on Linux Debian 8:</p>
  
  <p>i´m unable to send the test-mail via roundcube , it Returns the error : not ok
  and i´m also unable to do the test-Login via roundcube , it Returns the error
  Login failed for admin@mydomain from *** Unable to send command: A0002 LOGIN admin@mydomain</p>
  
  <p>i also tryed to re-install it  but it wont work </p>
  
  <p>can somneone help me with this ?</p>