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This feature is not universally available. Request Gmail Merge at helpdesk@lehigh.edu or request to join this Google Group which automatically provisions you in 24ish hours. https://groups.google.com/a/lehigh.edu/g/super-google-users-list which admins will review and approve. After approval (usually within a few hours) a process runs overnight to provision you. You may need to log out and log back in to see the feature.
Note that the feature does not appear to be supported in Safari, but works in Edge, Firefox, and Chrome.
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