I've received several query responses scribbled on my actual query. One was so badly scrawled I couldn't figure out for a while which one rejected me.
Another was a rejection, with a personal comment and an invitation to send other work sometime. A few have been requests for pages, including the note from my eventual agent. And of course, some just "not for us". One was a very snarky rejection, in fact.But the fact they were scribbled on my query didn't bother me.
You couldn't tell who rejected you when it was written on your actual query? The Dear Name didn't give you a clue? Don't tell me, oh do NOT tell me you sent a form letter. No, I refuse to believe anyone who reads this blog would do THAT...no no no.
One of my most delicious pleasures is confounding people who send "Dear Agent" letters.
Particularly if they don't include a header such as "Miss Snark, Snarkolicous Agenting and Tomfoolery, Address, etc".
Those queries DO get a hand written response. Very nice hand writing too. Dear -name-, I'm sorry I have to say no, but this isn't quite right etc.
Then I don't sign my name.
And I don't put my address on the SASE.
Then I wave ClueDust over the envelope and mail it.