How to set the from header for outgoing system email messages that are sent via msmtp on Ubuntu 16.04 LTS

I have setup msmtp on Ubuntu 16.04 LTS to deliver system email messages (cron, etc) to my inbox using an external smtp server.

I use the packages msmtp-mta, ca-certificates, heirloom-mailx

The configuration works fine. However emails that the system sends out, do not get the correct "from" email address. Instead my smtp service provider's domain appears in the from email address.

When I send a mail on the console, all is fine (as configured in /etc/msmtprc).

How can I fix this and have my domain name in those cron messages (also unattended upgrades messages)