Mail configuration

Hi everybody,

having installed successfully yunohost on a raspberry 1 B+, and having installed rainloop as a mail , i am facing the following problems:

  • I am receiving every few minutes the same message: ; Communication with server failed: timed out
    Unable to update IP address on DynDNS
  • I can receive emails but not sending.
  • I cannot install roundcube (even after having uninstalled rain loop).

Any hint ? Thanks in advance