How quickly do you reply?
In short: I try to reply to every message and email within three business days. A reply starts the conversation; it is not an opinion on value, authenticity or grade.
I run the practice myself, so replies come from me. I aim for three business days, and a complete first message (what you have, how many, and what the answer is for) usually means I can send a written scope in that first reply.
If you have a deadline, such as an insurance renewal or a filing date, put it in your first message so the scope can say whether it can be met.