I have 2 Zimbra servers that are dedicated mailbox servers, not running the MTA package. I need to be able to handle automated messages coming from cron and such. Since there is no postfix on these servers, there is nothing listening on port 25 to accept these messages. Is it safe to turn on the sendmail install that came with Red Hat? I have it disabled as per the install instructions. If not, how do I deal with this mail that seems to be building up in /var/spool/clientmqueue?