What first message to sellers actually want to receive?

**do, not to

I'm constantly seeing the line "don't ask if it's still available" or "will ignore if you ask if still available, if its here it's available", however I'm stumped as to what to ask because half of the time when I send off "would I be able to come and collect this today?" or a different message I'll get "sold" back!

What on earth do people want??