One approach towards reducing electronic junk, including spam in e-mail and on the Web, is to assign a small cost to the act of sending mail, or posting information on a Web site.

减少电子垃圾（包括电子邮件和 Web 上的垃圾信息）的一种方式是给发送邮件或在 Web 站点发布信息的行为加上一些成本。

youdao

Spam is unwanted sales messages sent to your electronic mailbox.

垃圾你不想要的讯息发到你的电子信箱。

youdao

Spam is unwanted sales messages sent to your electronic mailbox.

VOA: special.2009.04.19

Spam, too, became an electronic byproduct and not just a canned one, a problem that took AOL years to address.

MSN: AOL: You've got irrelevancy?

The CAN-SPAM Act, which is enforced by the Federal Trade Commission, established our first national standards for sending electronic mail.

FORBES: Facebook Strikes A Blow To Social Media Spammers