On responding to a startup funding no.
So you need money to get your venture going. I get it. And you’ve taken the spray + pray route to secure said funding (that is, you’ve sent basically the same email to every connection via email or LinkedIn). Now that I have your plea for investment, and taken the time to respond with a polite no (as I’m not actively investing right now), a smart networking suggestion would be to respond with a simple “thanks for letting me know” – as this would start to rebuild a connection after being subjected to inconsiderate mass-email haste.