"Big companies with large lists should focus on devising strong segmentation strategies.  List hygiene is incredibly important: make sure to not only regularly remove bounced email addresses, but also look at who is engaged. If you have subscribers that never open, click or buy your offerings, it may not be worth keeping them on your list? You want a healthy, active file. Check in with your subscribers. Ask them what they like and don’t like and remember to focus on three key factors - permission, engagement and frequency"

Read the entire interview here: Email deliverability: an interview with Return Path’s Mario Marlisa