PureMessage for UNIX is designed to integrate closely with sendmail and Postfix. It can also be configured to communicate with Oracle Communications Messaging Exchange Server. (On supported versions of Solaris only. See "Supported Mail Transfer Agents" in the "Installing PureMessage for UNIX" section of the documentation for more information.)
If, instead, you want to use PureMessage in conjunction with a mail system such as Microsoft Exchange, Lotus Notes, Exim, qmail, or an email appliance that is performing an additional function, you must deploy PureMessage in a relay configuration to protect these mail systems from viruses, spam, and other email threats.