Translation:I can read my email on my cell phone.
Not sure if it has been explained before, but "portable" could mean both "téléphone portable" or "ordinateur portable". A bit ambigous, even for the native speakers (at least in France) if the context is too vague.
I tried "tablet," and it was marked wrong. If both "phone" and "laptop" are included in "portable," why not tablets?
Because 'a tablet' is « une tablette ». « Un portable » only covers mobile phones and laptops.
That would depend how you define "correct". "Courriel" is from a group of words created in Quebec the 1990s to "encourage" people to protect their French cultural heritage by not using the technology terms from the other languages.
The term "Email" has been around since the seventies and is still commonly used. The French and Quebec governments have tried to get rid of it, but just like «weekend» , «email» is still a french word.
So, courriel is "the only correct term" if you work for or care about the opinions of L'Académie Française, L'Office québécois de la langue française or the government's in France or Quebec. But no one in any French speaking country that I know of is going to misunderstand you if you say «email» or the related term «mél» (which is short for messagerie électronique but sounds similar to both "mail" and «tél» in French).
Is "portable" still acceptable for smartphones today? I remember in high school (2009-11) French they would teach this word for those old flip phones.