@ does not work in message, ! appears instead

[axwell]

Hello,
when sending a simple message "!" apears instead of "@" for example send a message with test@test.com
If i send a message but with another word with diacritics "@" will appear ok, so i think the unicode detection is wrong.

        // get byte
        $byte = Helper::order(mb_substr($this->_data, $i, 1, 'UTF-8'));

        if ($byte > 0xC0) {
            $this->_isUnicode = true;
        }

can you help ? thanks !

[axwell]

Hmm i think the 7bit encoding is not treating @ ok.
https://www.developershome.com/sms/gsmAlphabet.asp