For PureMessage's list of currently supported platform versions, see the Sophos “Software lifecycle” web page.
https://community.sophos.com/kb/en-us/119019
If you are installing PureMessage on a 64-bit operating system, ensure that the 32-bit compatibility libraries (ia32-libs) are installed.
Ensure libnss-mdns is installed on your distribution.
The insaller may warn that you are not on a supported distribution. If the above conditions are me you should be able to proceed with the installation.
See Installing PureMessage on a 64-Bit Operating System in the Sophos Knowledgebase for more information.
set rlim_fd_cur = 1024 set rlim_fd_max = 4096
More detailed information on setting kernel parameters can be found in "Tuning PostgreSQL for PureMessage 5.x" in the Sophos Knowledgebase.