Bumping this back up to the top…
I figured out how to do this via EE’s contact_form module, but FreeForm is much more flexible when it comes to custom fields and I would prefer to use it instead.
This is what I have to run it through EE:
<select name="recipients" id="recipients">
{exp:weblog:entries weblog="staff" orderby="title" sort="asc"}
<option value="<?php echo base64_encode('{staff_email}'); ?>" {if url_title == segment_4}selected="selected"{/if}>{title}</option>
{/exp:weblog:entries}
</select>
Does Freeform still not cover this functionality provided by the contact_form module in EE?