If you have ever run into the problem that your computer will not send e-mails directly, then this might help.
Install Postfix and configure it as a satellite server. This was done on a Ubuntu desktop installation, so I don’t know what Fedora and co. will say.
In the /etc/postfix/main.cf file add or modify the following lines:
relayhost = smtp.gateway.ch smtp_sasl_auth_enable = yes smtpd_tls_auth_only = yes smtp_sasl_password_maps = hash:/etc/postfix/sasl_passwd smtp_sasl_security_options = noanonymous
This configures postfix to relay all e-mails over the defined host. Now the sasl_passwd file must be created with the credentials for the SMTP gateway:
Now create the map of the password file and reload postfix:
sudo postmap /etc/postfix/sasl_passwd sudo /etc/init.d/postfix reload
Test the configuration by sending a test e-mail:
echo -e "From: email@example.com\nTo: firstname.lastname@example.org\nSubject: Hello World\n\Body: \nHello beautiful world" | sendmail -t
And see what postfix said: