Which cost-effective email marketing tool do you know?

[Brajet]

I have a friend that just wants to start promoting his website. He told me that he's not a social media person. This makes using social media promotion is not really his way. He wants to make use of email marketing, especially because if is easy and as well cheaper when compare to other forms of marketing. However, he needs a cost-effective email marketing tool.
Do you have any one that can be recommended to him? Share it in the comment section.