Why doesn't searching on email with fuzziness work?

For some reason using fuzzy does not give any results on email fields. I use Haystack, but I figured out the ES queries itself are the problem:

This returns good results:
{ "query": { "query_string": { "query": "email:(jens.veraa@example.com)" }}}
This returns no results:
{ "query": { "query_string": { "query": "email:(jens.veraa@example.com~)" }}} (note the ~ at the end for fuzziness)

Can anyone help please? I looked through all the documentation for the query_string syntax to make sure it's not a char I need to escape, but it turns out that isn't the case.

Thank you,
Wim

It seems searching on the pattern jens.veraa@example.com* has to same problems. It does return results, but they are wildly irrelevant.
Further investigation tells me that up to the @-sign it wokrs well, but the moment you type the @ it stops working.