Is Tutanota replacement for Gmail ?

I begin to use Tutanota, which is free email produced by German company. Its feature is the secureness. It  makes sure that no one can spy on your secure emails. I am also using Gmail, which is most famous free email in the world. However, recently, its safety is concerned in all aspect. I found that Tutanota is easy to use. However, I cannot satisfied with its transmission speed to its server.