PHP if/else always going to else, even when IF is succesful

I have this foreach, which matches a postal code $searchvalue to an array of districts. The if statement does its job and executes succesfully, if there is no else.

However, when I uncomment the else, then the else is always executed.

Why is this the case?

foreach ($districts['district'] as $district) {
    if (in_array($searchvalue, $district['postalcodes'])) { //Search for known Postal Code
        $emails[] = $district['email'];

        //Assign new mail address
        $notification['to'] = implode("",$emails);

        //Continue sending email
        return $notification; //this succeeds without the else below. When the Else is uncommented, this is not executed.
    } 
    else {
        //No known postal code found, fallback
        echo "no valid postal code found, fallback";
        $notification['to'] = $defaultaddress;
        return $notification;
    }
}