I tried to install opendkim on the Ubuntu server using the Webmin command line, with the following command:
sudo apt-get -y install opendkim opendkim-tools
But I encounter a number of errors:
Setting up opendkim (2.11.0~alpha-11build1) ...
useradd: cannot lock /etc/passwd; try again later.
adduser: `/usr/sbin/useradd -d /var/run/opendkim -g opendkim -s /usr/sbin/nologin -u 111 opendkim'
returned error code 1. Exiting.
dpkg: error processing package opendkim (--configure): installed opendkim package post-installation script subprocess returned error exit status 1
Errors were encountered while processing:
opendkim
E: Sub-process /usr/bin/dpkg returned an error code (1)
I have seen this solution that suggests using SUDO, but this is an automated process that I have no control over
