email address in “from”

hi
how can i put a gmail address in “From” field?

i have a landing page where i put my business email with my domain.
the landing page address: https://www.domain.com
my email: [email protected]

i get hundreds of leads in an hour so my server is constantly blacklisted for spam.

how can i get hundreds of (legit, good) leads in an hour without having my server blacklisted?

thanks