Who is the standard mail-app in Windows 10, this may be possible in the future only in combination with the Edge browser. Microsoft is experimenting in a new test version of the operating system.
A link in an e-mail is always open in the Edge browser, regardless of whether this is your default browser. Microsoft choose the particularly for security reasons. Because the company used its own browser is the most secure, the less likely that users infected after clicking on a rogue link.
Silliness, of course, because Chrome and Firefox are also perfectly capable of dangerous websites on time to intercept. It is also very doubtful whether Microsoft plan to continue. First ask the company for feedback from Windows 10 testers. The company has all the time to make the decision to turn back. This change could, in fact, not until the end of 2018 for the regular version of Windows 10.