Basically I have a select in my freeform, say with values catalogue A, catalogue B, catalogue C. Is it possible to set the email recipient depending on the value that the user will select? e.g. requests for catalogue A,B should go to one email address, catalogue C to another one. Any advice appreciated!
FreeForm actually has a Dynamic Recipients field that sounds like it will do what you're wanting. I believe you can choose to have it displayed as a select field, radio buttons, or checkboxes.
Alternatively, you could probably create a little custom Twig and set up dynamic template notifications. I would think you should be able to switch the recipient array there based on the value of your select field for each submission (but it's possible I'm wrong; the Dynamic Recipients field definitely seems like the better option).