gentoo-overlay/mail-mta/ssmtp/metadata.xml

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE pkgmetadata SYSTEM "http://www.gentoo.org/dtd/metadata.dtd">
<pkgmetadata>
  <maintainer type="project">
    <email>net-mail@gentoo.org</email>
    <name>Net-Mail</name>
  </maintainer>
  <use>
    <flag name="mta">Install symlinks for sendmail-compatible MTA.</flag>
  </use>
</pkgmetadata>