What feature assists in personalizing email content with user-specific details?

The feature that assists in personalizing email content with user-specific details is email tags. Email tags allow users to include dynamic content within their messages, such as the recipient's name, location, or preferences. This personalization leads to a more tailored communication experience, making emails feel more relevant and engaging to the recipients.

By incorporating email tags, senders can automatically replace placeholders in the email body or subject line with information that is unique to each recipient. This capability enhances user engagement and increases the likelihood of the email being opened and acted upon, as it resonates more with individual recipients.

Other options like email settings, which pertain to configuration preferences, or email subject lines alone, which do not include the dynamic replacement of user-specific information, are not directly related to personalized content. Email group selection pertains to the targeting of specific groups rather than customizing individual messages, hence lacking the personalization aspect that email tags provide.