Address munging is the practice of disguising, or munging, an e-mail address to prevent it being automatically collected and used as a target for people and organizations who send unsolicited bulk e-mail. Address munging is intended to disguise an e-mail address in a way that prevents computer software seeing the real address, or even any address at all, but still allows a human reader to reconstruct the original and contact the author: an email address such as, "no-one@example.com", becomes "no-one at example dot com", for instance. Any e-mail address posted in public is likely to be automatically collected by computer software used by bulk emailers — a process known as e-mail address harvesting — and addresses posted on webpages, Usenet or chat rooms are particularly vulnerable to this. Private e-mail sent between individuals is highly unlikely to be collected, but e-mail sent to a mailing list that is archived and made available via the web or passed onto a Usenet news server and made public, may eventually be scanned and collected.

Disadvantages
Disguising addresses makes it more difficult for people to send e-mail to each other. Many see it as an attempt to fix a symptom rather than solving the real problem of e-mail spam, at the expense of causing problems for innocent users.
Disguising e-mail address in a systematic manner (for example, user[at]domain[dot]com), is just as bad as not disguising the address at all as such addresses can be revealed through a simple Google Search.

Alternatives
As an alternative to address munging, there are several "transparent" techniques that allow people to post a valid e-mail address, but still make it difficult for automated recognition and collection of the address:
An example of munging "user@example.com" via client-side scripting would be:
The use of images and scripts for address obfuscation can cause problems for people using screenreaders and users with disabilities.
According to a 2003 study by the Center for Democracy and Technology, even the simplest "transparent name mangling" of e-mail addresses can be effective.