At LashBack, senders are often approaching us asking whether they should use the list-unsubscribe header. By and large, the biggest concern many senders have is the impact the use of the list-unsubscribe header may have on deliverability.
While the presence of the word 'unsubscribe' may be perceived as a sign of commercial email, I am not aware of any cases where messages may be filtered for the mere presence of this word, yet alone the list-unsubscribe header. Several years ago, Spam Assassin did assign points for the list-unsubscribe header, but these tests were moved in version 3.0 (http://spamassassin.apache.org/tests.html).
If filtering companies and ISPs were to filter mail based on the list-unsubscribe header, they'd be filtering some of the best mail that consumers want, including the following:
Bath And Body Works
And MANY more (if you'd like a full list, let me know)
Without spelling out all the benefits of the list-unsubscribe header, I urge senders to ignore any fears of a negative deliverability impact. Next time, I will spell out how it can actually improve deliverability.