Connection with multiple database where the second is randomic

Hi guys, today i have two connectios, first in mysql and the second in sqlite, but the second one is randomic, because is correspond an email DB, and in my server i have a folter to each mail and each mail have a connection, a new DB connection, how i can make a randomic connecion with sqlite, i think i can not use the .env settings becouse the database is not one, someone can help me.