Using Civi for a signposting service
welcome to civi and SE.

There are a number of ways to address the requirements and partly would depend on your CMS.

For example with Drupal you can use Webform module (with civicrm integration) as a simple way of recording an interaction, then choosing the required 3rd party, pulling in their email and therefore sending an email, from Webform. The text of that email can be tweaked to provide whatever information needs to be passed on to them.

In pure civi this would be handled by creating an Activity and 'assigning' it to the 3rd Party, and this causes CiviCRM to fire off an email (assuming that setting is 'on' for your system) but you don't have much control, out of the box, as to what gets sent.