sendmail requires msmtp alias

In order to prevent logwatch from reporting the following mail sending error:

sendmail: recipient address root not accepted by the server

it is necessary to add an alias for use by msmtp. This requires modifying /etc/msmtprc:

# Defaults for all accounts
defaults
auth on
tls on
aliases /etc/aliases

The following should then be added to /etc/aliases:

root: <recipient@domain.com>

replacing recpient@domain.com with the address to which all emails related to system security are to be sent.