http://biccari.altervista.org/c/informatica/gentoo/msmtp.php
https://wiki.archlinux.org/index.php/Msmtp#Using_msmtp_offline
https://www.techrapid.co.uk/raspberry-pi/how-to-send-email-on-raspberry-pi-from-command-line-with-msmtp
https://wjianz.wordpress.com/2014/09/03/howto-installconfigure-msmtp-and-mutt-on-ubuntu/


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# Set default values for all following accounts.
#
# echo -e "Subject: Test Mail\r\n\r\nThis is a test mail" |msmtp --debug --from=default -t username@gmail.com
#
# chmod 600 /etc/msmtprc

defaults
#logfile        /var/log/msmtp.log
syslog          on
aliases         /etc/aliases 

# gmail address
account         gmail1
host            smtp.gmail.com
port            587
auth            on
from            nome.cognome@gmail.com
user            nome.cognome@gmail.com
password        passwd
tls on
tls_starttls on
tls_certcheck off
#tls_trust_file /etc/ssl/certs/ca-certificates.crt

# gmail address
account         freeprovider
host            smtp.provider.com
from            nome.cognome@provider.com
...
...

# Set default account
account default: gmail1
-----------------------------------