Various anti-spam techniques are used to prevent email spam (unsolicited bulk email).
No technique is a complete solution to the spam problem, and each has trade-offs between incorrectly rejecting legitimate email ( See more

There are a variety of techniques that email senders use to try to make sure that they do not send spam. Failure to control the amount of spam sent, as judged by email receivers, can often cause even legitimate email to be blocked and for the sender to be put on See more

Several approaches have been proposed to improve the email system.
Cost-based systems
Since spamming is facilitated by the fact that large volumes of … See more

There are a number of techniques that individuals can use to restrict the availability of their email addresses, with the goal of reducing their chance of receiving spam. See more

There are now a large number of applications, appliances, services, and software systems that email administrators can use to reduce … See more

From 2000 onwards, many countries enacted specific legislation to criminalize spamming, and appropriate legislation and enforcement can have a significant impact on spamming activity. Where legislation provides specific text that bulk emailers must include, this … See more

• AOL's postmaster page describing the Anti-Spam Technical Alliance (ASTA) Proposal
• Anti-Spam Research Group wiki, which was created by ASRG and is still alive
• Anti spam info & resource page of the US See more