[Exim] regex and email validation

Hello, i am trying to make a ACL the deny emails
with strange characthers, like:

  deny    senders       = !
^.[a-z0-9_-]+(\.[a-z0-9_-]+)*@[a-z0-9_-]+(\.[a-z0-9_-]+)+

If somene issues:

mail from: tést@???

it will deny, but

mail from: test%as@???

it will not deny...

Is this regex wrong ? anyone know a better (regex or something else) way to
only
allow [a-z0-9_-] validation ?

Aba