Set Up Email Forwarding from Hostinger to Gmail (Keep Existing Apple Mail Working)

Hi, I need help setting up email forwarding for my business while keeping my current setup intact. What I need: • Forward all new emails from my Hostinger-hosted work email address to my Gmail inbox • Keep a copy of forwarded emails in the original Hostinger mailbox as backup • Important: Do not change or break my existing IMAP/SMTP access. I currently have everything working perfectly in the Apple Mail app on my phone (using port forwarding on my router to reach the mail server). This must continue working exactly as it does now with no changes to server hostnames, ports, MX records, or anything else. • (Optional but preferred) Set up Gmail’s “Send mail as” feature so I can reply to clients using my work email address from Gmail