As we don't know the noun to which the indirect pronoun it refers it could also mean you (the formal you indirect pronoun is also le).
Yo le doy (a usted) un mensaje importante
Yo le doy (a ella) un mensaje importante
Yo le doy (a él) un mensaje importante
Because the third person indirect object pronoun is gender neutral, it is common to maintain the indirect object phrase in the sentence for clarification.