For instance, you're limited to only a single campaign with no access to stats or even the ability to view your suppression list.
I requested a refund. I'm not alone. If you look at their JVZoo stats, you'll see they're having a lot of refunds requests.
However, it's been several days, and I can't get them to honor their money-back guarantee.
First, they ignored me. Then, they told me I could upgrade for a discount. I keep insisting on a refund, and as of right now, still haven't received one.
There are many options for doing mass mailings out there that are superior and less expensive.
Avoid MailZingo like the plague.