Experts say instances of vote by mail fraud are rare.

专家称，通过邮件进行投票的情况非常罕见。

The FBI is also involved in " mail fraud" cases, where people are using the United States mail system to lie and steal, usually money, from other people.

FBI 还参与了“邮件欺诈” 案件，人们利用美国邮件系统撒谎并从他人那里窃取（通常是金钱）。