Benchmark is a tool for managing mass emailing. It is great for marketing or for staying in touch with large groups of people via email. The tool makes it relatively easy to create nice looking HTML-based emails. And the tools for managing various mailing lists are quite nice.
The pricing plans are a bit complex, and I frequently find myself bumping up against the ceiling of my current plan. I can't justify going to the next plan up, so I have to pare something back. The learning curve was a little steep, but, once I got the hang of it, I was OK.
I doubt Benchmark could do anything about this, but the fact that I have to maintain two copies of a mailing list, one in Benchmark and one in my CRM, is worrisome. What if they get out of synch (and they do frequently)? But there are tools for importing .csv files, so that's how I keep things in synch.
There are other products out there -- MailChimp being the main competitor -- but I like Benchmark better. Admittedly, part of that may be because I'm now very familiar with it, although we did consider MailChimp when we first were looking for a tool to handle mass emails. Make a matrix of features you're looking for and do a good comparison. Watch out for the complex pricing matrix, too -- there are many ways to buy Benchmark and it really depends on your situation which package is right for you.
We have several mailing lists we use to communicate with large groups of people. Benchmark allows us to maintain our lists (although it isn't integrated with our CRM), design nice emails, and get them sent out. It tracks bounces and returns nicely and lets us get a good sense of which emails are most effective. It even has an A/B test for the email subject line that has yielded some surprising insights for us about what works and what doesn't.