Prophet (peace be upon him) said: When someone dies, their acts come to a halt, except for three; Sadaqah Jariyah (ongoing charity), knowledge (by which people) benefit, or a pious child who prays for them (for the deceased).
As for what he (peace be upon him) had said that whoever conveys blessings upon him, their blessings will be submitted to him, this is a distinctive feature relative to conveying blessings upon him, for whoever conveys blessings upon him (peace be upon him) once, Allah (Exalted be He) conveys blessings upon them tenfold.
He (peace be upon him) also said: Convey more blessings upon me on Friday, for your blessings will be submitted to me. People asked: "O Messenger of Allah, how can this be while your body will be decomposed?" He said: "Allah has prohibited the earth from consuming the bodies of the prophets."
This ruling is restricted to conveying blessings upon him. Moreover, it is reported in another Hadith that he (peace be upon him) said: Allah has roaming angels who convey the blessings of my Ummah to me.
This is a distinctive attribute of the Messenger (peace be upon him), and he is being informed about that.