The complete prerequisites for installing PureMessage for UNIX can be found in the "Installing PureMessage for UNIX" section of the documentation. For suggested server configuration, see PureMessage: memory and CPU power needed on the server.
Apart from a supported platform and 500 MB of disk space for the initial installation, PureMessage has few installation prerequisites. Additional disk usage will vary according to your mail volume.
A custom and self-contained version of Perl is included in the PureMessage installation.
PureMessage includes versions of both sendmail and Postfix. However, external installations of Postfix, sendmail, Sendmail Switch, and Oracle Communications Messaging Exchange Server are also supported. See the "Supported Mail Transfer Agents" section of "Installing PureMessage for UNIX" in the documentation for the specific versions.