Which E-Mail provider would you say is the safest to use? None.
I use several different e-mail providers. Frankly, in my opinion, I think if you are using any e-mail provider, then there are risks involved, and it does not matter what the e-mail provider says to you, or anyone else, for that matter.
I read, and hear about people infecting their computers, and these people don't know what happened to their computers.
Some people have stupidly sent me different kinds of computer infections, and nobody seems to realize that I won't download something on my computer if I don't know what I would be downloading.
There are other issues that are more technical regarding e-mails that probably few people know about. Believe me when I say, if you don't know much about e-mails, then you could easily make a mistake, and do something you will regret later on.