How to (sort of) get slackware security update notifications on your xfce desktop:
1. Grab alienbob's excellent rsync_slackware_patches script, and place it in /usr/local/bin (or somewhere you prefer in your $PATH)
2. Add rsync_slackware_patches.sh to your crontab, e.g. :
10 17 * * * /usr/local/bin/rsync_slackware_patches.sh -q -r 14.1
3. Create a .forward file in /root, forwarding mail to whatever user you log in to your desktop with, e.g. user@localhost
4. Enable sendmail: chmod +x /etc/rc.d/rc.sendmail ; /etc/rc.d./rc.sendmail start
5. Install xfce4-mailwatch-plugin from slackbuilds.org
6. Add the mailwatch plugin to the desktop (right click panel, Add New Items, Mail Watcher)
7. Configure the mailwatch plugin to watch mail for yourusername@localhost (Add, Select Mailbox Type: local mbox spool, mailbox location is /var/mail/user)
When the rsync_slackware_patches cronjob runs, if any updates are found, cron will mail root. The mail will be forwarded to your desktop user account, and the mail watcher will indicate new mail. Run slackpkg update and slackpkg upgrade-all.
This is a hackish solution and it won't suit a lot of setups - especially if forwarding root mail isn't a viable option.
It won't notify you about updates for software installed with sbopkg or other third-party package managers. Still, it works well enough for a single-user desktop slackware install and is
useful if you have a habit of not keeping a close eye on the
slackware-security mailing list.
Don't leave sendmail open to the world - adjust your sendmail config and firewall accordingly.
This works for me, your mileage may vary. Tested on Slackware 14.1, 32-bit.