Hi there,

You can add codes below on your emails accordingly.

[gist type="php"]
<?php $user = ES::user(); ?>
//URL are used for object name, change them acordingly
<?php $URL = $user->getFieldValue('URL'); ?>

<?php if ($URL instanceof SocialFieldValue && $URL->data) { ?>
<li class="o-nav__item t-text--muted t-lg-mb--sm">
<i class="es-side-widget__icon fa fa-link t-lg-mr--md"></i>
<?php echo $URL; ?>
</li>
<?php } ?>

[/gist]

Codes below are example only, you can find each unique field here http://take.ms/921W1, you can apply those unique key into getFieldvalue('insert here');

You can check those emails template here http://take.ms/MXN6a and for registrations, you can check them accordingly here http://take.ms/pirkJ

Please give it a try and see how it goes.