gentoo-overlay/dev-libs/gmime/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "https://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <maintainer type="project">
    <email>gnome@gentoo.org</email>
    <name>Gentoo GNOME Desktop</name>
  </maintainer>
  <upstream>
    <remote-id type="github">jstedfast/gmime</remote-id>
  </upstream>
  <use>
    <flag name="smime">Enable experimental S/MIME support</flag>
  </use>
</pkgmetadata>