Long and Short Forms of Russian Passive Participles

Did you know that Russian past passive participles can have both long and short forms? Long forms are used for descriptions and short forms to express facts in passive constructions.

For example,

1.  Мейл, написанный им вчера, был очень длинным. The email, written by him yesterday, was very long (Description).
2. Мейл был написан им вчера. The email was written by him yesterday (Fact).