Msmtp does not understand `/etc/aliases`

I have configured my Debian server to use msmtp for sending mails. Current use case are for example sending a daily report from logwatch to my isp email. echo "$body" | mutt -s "$topic" -- "myisp@email.com" I have configured msmtp by means of a global msmtprc file located at /etc/msmtprc. Contents shown below. The next thing I want to configure is that my email for my root account (e.g., output from crontabs) is sent to my isp email as well. I have googled around and found, for example on the Arch wiki, that I should just configure my aliases. Which I have done so at the bottom of the msmtp configuration file. However, after running newaliases, and trying to execute echo test | mail -s "test message" root I get the error send-mail: /etc/aliases: line 2: invalid address 'postmaster' Can't send mail: sendmail process failed with error code 78 I am unsure how I can fix this. The alias shown below is what was already present. I only added the gmail address. I think I could just put a new aliases file but that might break other services that rely on this. I.e., I don't know what the proper way to fix this is. # /etc/aliases # /etc/aliases mailer-daemon: postmaster postmaster: root nobody: root hostmaster: root usenet: root news: root webmaster: root www: root ftp: root abuse: root noc: root security: root root: christphe, christophe.detroyer@gmail.com # /etc/msmtprc # ------------------------------------------------------------------------------ # msmtp System Wide Configuration file # ------------------------------------------------------------------------------ # A system wide configuration is optional. # If it exists, it usually defines a default account. # This allows msmtp to be used like /usr/sbin/sendmail. # ------------------------------------------------------------------------------ # Accounts # ------------------------------------------------------------------------------ account isp host mail.isp.net port 587 from admin@isp.com auth login user admin@isp.com password foobar syslog LOG_MAIL logfile /var/log/msmtp.log # ------------------------------------------------------------------------------ # Configurations # ------------------------------------------------------------------------------ # Construct envelope-from addresses of the form "user@oursite.example". #auto_from on #maildomain fermmy.server # Use TLS. tls on tls_starttls on tls_trust_file /etc/ssl/certs/ca-certificates.crt # Syslog logging with facility LOG_MAIL instead of the default LOG_USER. # Must be done within "account" sub-section above #syslog LOG_MAIL # Set a default account account default : isp aliases /etc/aliases # ------------------------------------------------------------------------------#