I've installed exim4 on my ubuntu server using this tutorial.
So now I can send emails via terminal with:
echo "This is a test." | mail -s Testing email@example.com
And I get email from firstname.lastname@example.org
But how to send e-mails from some specific name like My-New-Mail@mydomain.com.
I think I have to create a new Ubuntu user and then to do something to exim4 configuration.
But how exactly? And how to do it secure for my system?