The Barracuda appliance works well.
I've deployed ~35 units. It's trainable, easy to configure and provides 99%+ of the desired functionality in a spam filtering solution. I can't think of many additional requests.
I tend to handle the initial configuration, then hand it off to a designated user or local administrator at my client sites. It's easy enough for a non-technical user to manage on an ongoing basis.
Note, there is also a virtual machine option, which solves some of their hardware deficiencies.
I find that the controls and filtering are more granular than some cloud-based solutions. Also remember that some organizations don't want mail being funneled through an external site.
That said, the initial costs and the maintenance fees associated with the Barracuda physical appliances are a downside for smaller organizations. There have been some ugly policy and support situations, too... All of my complaints are support and policy-based, and not with the actual operation of the unit.
- The hardware is expensive, but cheap. It's low-quality gear.
- The OS (or "firmware") is a customized Linux and it runs entirely in RAM (ramdisk). Some older units don't have enough RAM to accommodate, so they swap heavily, killing performance.
- Depending on where you buy your unit, the hardware could be from any generation or have been silently revised.
- Sometimes you'll find that your hardware will be stuck at a particular software revision level. Rather than say, "your gear is too old", you simply won't receive firmware updates.
- The warranty and support are non-transferrable.
- Any lapses in warranty coverage require you to backdate pay/"catch up" to the point where coverage ended. This kills the used appliance market.
- Sometimes, you need to open a support connection (reverse SSH tunnel) for basic maintenance like clearing logs or freeing disk space.
- Hardware problems aren't really covered without a fight. Barracuda will try to push you into the "Instant Replacement" support tier (which really means a cross-shipped unit).
- The occasional bug...