I've been using this for years with multiple clients both large and small. It's very reliable and easy to use for any size client. Not much dislike as it is just so effective - but you can't set up rules like you would in other mail servers if you want them to work seamlessly with all your existing apps. We have not had issues with support since we started using their product several years ago. Use it. You won't be disappointed. It works great for our needs. If they ever discontinue it or stop providing updates then it will lose its value quickly. Sending newsletters for an event where attendees are spread across different states within the US. This makes them feel more personally connected when they receive emails directly related to them versus having to go through another organization/company first.