Contacts who unsubscribe from your lists are taken from your active lists and automatically put in the Unsubscribed status. You can manually mark contacts as unsubscribed as well.
You work hard to provide a flawless user experience and your unsubscribe process should also be on par. Make the effort to brand your unsubscribe confirmation pages and emails just like you would your opt-in form. You want this to be a lasting impression in a good way.
Make it easy for people to opt-in to your list on your website, your blog and social media channels like Twitter and Facebook because you never know when they’ll change their minds.
Attrition will cause a yearly loss of about 30% of your email list, so keep in mind that growing your list is an on-going process. Then, living up to the promise you delivered when people opt-in is most important. Give them what you promised and you’ve won half the battle.