Why "se" lo manda a ....

[mwtzzz]

can someone explain the rationale behind the "se" in the following:

ya se lo mandó a ella?
se lo voy a enviar a la mia

[AngelicaDeAlquezar]

"Se" is an indirect object pronoun referring to "a ella" and "a la mía". They're redundant, but sometimes the speaker finds them necessary.

[mwtzzz]

"se" replaces the usual "le" when in front of a "lo" o "la" direct object pronoun so that's its easier to say

[Rusty]

Exactly. It sounds better. That's the rationale behind the use of 'se' in this particular structure.