Cannot use Smarthost

Hi all,

I would create my personal account under It domain but using the provider’s pop3 server to receive mails.
What I want is to use NethServer to send mails and the provider’s pop server to receive incoming mails so I’m trying to set up Smarthost for the outgoing ones.
I tried several providers (,, but I cannot make it work.
With some providers all the mails remain in the exit list but they aren’t sent, using e.g. or (my connection is cellular connection type), I always receive the following error message:

Diagnostic-Code: smtp; 550 Invalid Mailfrom [smtp-16.iol.local; LIB_430]

What I make wrong in setup parameters?
Thanks in advance for your kindly support.

Hi Luciano,

Do you have a valid domain (public not .local)?
Did you check your DNS settings?

Maybe this will help you:


Try here, also at “Commenti”:

And here:

Please check all your email settings.

you must provide us many other info about your setup