"文字化けしてるよ(it's garbled)”

In English, it's saying,

The text in the email you just sent is all garbled.

だそうだ。

"garble"?? I've never seen this word.

garble v. reproduce (a message, sound, or transmission) in a confused and distorted way

: the connection was awful and kept garbling his voice

: I got a garbled set of direction.

n. a garbled account or transmission.

(from Oxford dictionary)

始めにあったものを再現しようとしたら、おかしな形になってしまったね、

というニュアンスらしい。言い得て妙、という感じ。

Almost all of them are kanji(漢字). 

But  anyone, even Chinese or Japanese, cannot read them...