Mystrika is pretty good so far, but it took some time to get used to it.
I am into Domain reselling business and it has already paid for itself.

If you are looking for cold email tool, then this one you should definitely get.

**Update** After an year almost.
Mystrika has already re-paid me many times over, and going in strong.
Amazing cold email tool and service. Hats off to their team on answering all questions in their facebook group.