The electronic mail address of a person or institution
The address element <email> is allowed as part of a paragraph as well as inside an address.
Text, numbers, or special characters
... <aff id="hhMI">Department of Molecular, Cellular, and Developmental Biology, Howard Hughes Medical Institution, University of Colorado, Boulder, Colorado 80303-0347</aff> <author-notes> <fn id="FN150" symbol="*"><p>Corresponding author. E-mail address:<email>firstname.lastname@example.org</email>.</p> </fn> </author-notes> ...