Email list cleaning refers to the process of removing bad and inactive addresses from an email list.
Email list cleaning allows to have better deliverability and better visibility on email marketing performances. Unclean lists are a bad sign for ISP and a call for filtering or blacklisting.
List cleaning steps are:
pre-campaign email addresses verification
web form typos prevention
auto typo fixing
feedback loop management
inactive subscribers removing (to adapt to engagement-based filtering)
role accounts removing (firstname.lastname@example.org, email@example.com)
Email list cleaning is a necessity but may raise some issues. Thus, after removing inactive subscibers on an old list, it is not always easy to explain the line manager why an email list is cut in half.
Not cleaning a list leads mechanically to lower open and click rates because of filtering issues and ghost suscribers proportion.