# If persona_allowed_domains is set, check if the email address returned is on these domains.
    # When not configured, allow all domains.
    my $allowed_domains = $c->config->{persona_allowed_domains} || "";
    if ( $allowed_domains ne "") {
        my $email_ok = 0;
        my @domains = split ',', $allowed_domains;
        map { $_ =~ s/^\s*(.*?)\s*$/$1/ } @domains;

        foreach my $domain (@domains) {
            $email_ok = $email_ok || ((split '@', $email)[1] eq $domain);
        }
        die "Email address is not allowed to login." unless $email_ok;
    }