Why does Gmail sometimes not display the list-unsubscribe header?

Email marketer from Email Geeks indicates that they have observed inconsistent display of the unsubscribe link for different customers, attributing it to reputation differences.

Email marketer from Email Geeks shares that Gmail uses a reputation score to determine whether to display the list-unsubscribe header, suggesting that a lack of sufficient reputation data can prevent the link from appearing, even if everything is correctly set up.

Email marketer from Mailjet explains that improving sender reputation involves consistently sending valuable content, segmenting lists effectively, and promptly removing unengaged subscribers. A good sender reputation increases the chances of Gmail displaying the list-unsubscribe header.

Email marketer from Email on Acid explains that clean and accessible email code is also very important. If the code is inaccessible the email may be put in spam which would impact the reputation.

Email marketer from StackOverflow suggests checking if the List-Unsubscribe header is correctly formatted and encoded. Incorrectly formatted headers may be ignored by Gmail, preventing the unsubscribe option from appearing.

Email marketer from Campaign Monitor shares it is important to keep your email lists clean and updated. If you don't then email providers like Gmail may struggle to correctly parse your emails and not show the unsubscribe header.

Email marketer from Email Geeks shares a link from Google noting reputation as a factor in displaying the unsubscribe link.

Email marketer from Reddit shares that Gmail considers spam complaint rates, sender authentication (SPF, DKIM, DMARC), and engagement metrics when deciding whether to show the list-unsubscribe link. Higher spam rates and poor authentication can suppress its display.

Email marketer from Litmus explains that correctly implementing DMARC can help with this issue, they share that Gmail are more likely to display unsubscribe if you have it properly setup.

Email marketer from Neil Patel's Blog shares that Gmail's algorithms consider various factors for deliverability, including sender reputation, engagement, and spam complaints. A poor sender reputation, triggered by low engagement or high spam rates, might prevent the display of the unsubscribe link.

Expert from Email Geeks explains that Offering to unsubscribe in place of a TiS is a _strong_ statement on Googles behalf that they know enough about this sender to treat them as a trusted partner and that they trust the sender over the recipient. They're saying they don't think this is spam, even if it's mail you don't want.

Expert from Email Geeks confirms that Gmail's display of the list-unsubscribe header is indeed influenced by reputation, as Google has stated.

Expert from Word to the Wise mentions list engagement as crucial. Low engagement can lead to deliverability issues. If Gmail notices your recipients aren't engaging, they might not show the unsubscribe link.

Expert from Email Geeks shares that If they don't trust the sender you get a TiS action instead of an unsubscribe action. Much the same result for the recipient, so no real loss of functionality.

Expert from SpamResource explains that Gmail's decision to display or suppress the List-Unsubscribe header is heavily influenced by sender reputation. Senders with a poor or unknown reputation are less likely to have the header displayed to Gmail users.

Expert from Email Geeks shares that If they've never seen mail from you, they don't trust you enough to offer an unsubscribe. They may trust you enough to deliver to the inbox.

Expert from Email Geeks explains that integrating unsubscribe into the MUA is Google vouching for the trustworthiness of the unsubscription process, and they will only do that if they actually trust the entity they're sending information to on behalf of the recipient.

Documentation from SparkPost explains that the presence of a list-unsubscribe header doesn't guarantee its display in Gmail. Gmail's algorithm evaluates sender reputation and user engagement before showing the native unsubscribe option. In some cases, Gmail may prioritize its own unsubscribe mechanisms.

Documentation from Twilio SendGrid explains the need to set up authentication correctly. DMARC is the first check that stops you going to spam.

Documentation from RFC 2369 (the standard for the List-Unsubscribe header) explains while the header specifies how to unsubscribe, it doesn't dictate how or if email clients will display that option. Gmail can choose to ignore or prioritize other factors.

Documentation from Google Support explains that Gmail automatically displays an unsubscribe link if you send many emails at once. This is not the list-unsubscribe header specifically, but Gmail's own implementation, and its appearance can vary based on Gmail's algorithms.