In addition to everything said above, “FedEx” isn’t derived from a third declension Latin noun. That’s also why the plural of “hex” (which comes from German) is “hexes” rather than “heicis” or “heges.”
I generally say that I’[m expecting some FedEx packages…OR…I’m expecting some packages from FedEx. There’s only ONE FedEx so it shouldn’t be plural to begin with!!!
@elbanditoroso But that would not be precise use of the term. You can’t say that people who slaughter the language use it properly. The correct answer to the question requires proper use of the language.
a) Fedex designates a specific company and plural of that does not actually make sense, except possibly in some hypothetical exercise.
b) Vortex is a Latin word and vortices is the correct way to form its plural, while FedEx is not a Latin word, it’s a name of a company headquartered in a English-speaking country. Plurals of English words that end in “X” sound form a plural with ‘es’ => Fedexes, for what it’s worth.