Let people know exactly what they’ll be receiving before they sign up for your list.
Keep your list clean. When you get bounces, both hard and soft, remove them. Make sure you’re not sending to those email addresses again. List hygiene will help ensure you are a reputable sender. Start List hygiene after your first send.
Send to people that actually signed up for your emails.
Send relevant, interesting, and engaging emails that have a purpose.
Make it easy to unsubscribe. If you are sending like you should, people will be likely to stick around.
Have a clear and useful preference center. Ask about what people like to receive so you can send the right message to the right people.
If you haven’t been sending to a large list for a decent amount of time, throttle the sends for a bit. Throttling sends the email in chunks over a period of time instead of all at once.