With “may be” we have two verbs, while “maybe” is an adverb meaning possibly or perhaps (quizas).
Here are two examples that show the difference:
• Maybe (quizas) Mr. Podemos will go and live in Venezuela or North Korea to appreciate (apreciar) the lunacy (la locura) of his policies.
• He may be (“might be” is also an option) more at home in Venezuela or North Korea (es possible que pudiera sentirse más en casa en ….).
That may be true, or maybe not. You know the answer.