I just wrote to someone,
Tell Alivia Wyatt says hi.
Am I missing a comma? It seems like there almost has to be one between the names. I find it a strange sentence to punctuate.
A comma would not make sense there, but using "that" in between Alivia and Wyatt would provide the separation that you are perceiving is needed.
If you're worried, you could put quotes round Wyatt says hi. Compare:
Come to that, you could also put quotes round hi, as it's reported speech.
This is a simple imperative statement, with the implied subject "you", the verb "tell", indirect object "Alivia", and direct object "Wyatt says hi".
In this case, one would not use a comma between the two names. Consider an equivalently structured sentence.
We would not write
as this would seem to say that I am the ball, and you should throw me.
Putting a comma between the two names would change the meaning, and would seem to say "Tell Alivia (something, probably specified in the previous sentence), because/and Wyatt says hi."
This is a more complicated issue than most simple commands, because the object is both an entire sentence on its own, and a direct quote.