Chromebook by default uses GMAIL web view in fact your log in to the CB is your log in to GM.
I use a different free E-mail Service's web view
I do not do client mail Client emal apps are the way to infection With an E-mail client on your comptuer it downloads all The E-mail including any virus programs and then have fun cleaning the drive.. Last Client I used was NetTamer and though I saw many Virus files downloaded... Well it is a DOS program not windows so they did no harm and were tossed un-decoded.
With the Web Mail services I once tried to download a known infected file.. I gave up.. Warning after "Do you really want to do this" after warning after.. Well you get the idea.