Three years ago, I sent a letter to the manager of a well-known actress about a screenplay I had co-written. I dispensed with any "To whom it may concern" BS because that kind of formal tone will get you nowhere. My letter? It was funny. And so the manager called me and asked to see the script. I was later told that my breezy summer comedy was not a good fit for her client.
Fast forward to 2021. Two months ago, I contacted her again, telling her that I had co-written a sitcom pilot and that her client would be perfect in the lead. Once again, she requested to see the script. Alas, nothing came of that either. Well, so far, because I haven't heard back. But seeing this was two months ago, I'll take her silence as a second rejection. *sigh*
However, here's the thing: that she asked to see the second script means she liked the first script even though she said no it. Translation: If she thought the first script was no good or poorly written, she wouldn't have asked to see the second script.
So while I remain unsigned and unloved, my experience shows, as this essay confirms, that managers will get back to you.