Address munging
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Address munging is the practise of disguising, or munging, an e-mail address to prevent it being automatically collected and used as a target for people and organisations who send unsolicited bulk e-mail.
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Intent
When an undisguised e-mail address (e.g. "no-one@example.com") is posted in public it is easily recognised and collected by computer software. A collected address will then become a target for unsolicited bulk e-mail. Address munging can be used to prevent the use of software recognition for large-scale harvesting of addresses, while giving enough clues for a human reader to easily reconstruct the correct address and contact the author.
Any e-mail address posted in public is subject to scanning and collection, including those posted on webpages or onto Usenet. Private e-mail sent between individuals is unlikely to be scanned and address munging is unnecessary in this case. However, e-mail sent to a mailing list, which is then archived and made available via the web or passed onto a Usenet news server and made public, may eventually be scanned.
Examples
A common method of disguising an address is to replace the "@" symbol with the word "at", and any "." with "(dot)" giving a result that does not look like an e-mail address at all:
- no-one at example (dot) com
There are many other methods for disguising the address:
| Disguised address | How to recover the original address |
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| no-one at example dot org | Replace "at" with "@", and "dot" with "." |
| no-one@elpmaxe.co.uk.invalid | Reverse domain name example remove .invalid |
| ten.elpmaxe@eno-on | Reverse the entire address |
| no-one@exampleREMOVEME.com.invalid | Instructions in the address itself; remove .invalid |
| no-one@exampleARCHIMEDES.com.invalid | Remove the mathematician; remove .invalid |
| no-one@example.com.invalid; s/example/no-where/ | Substitute no-where for example; remove .invalid; See Sed for a description of the s// syntax |
Some of these methods still result in a recognisable e-mail address, but an incorrect one. This is less satisfactory as anything resembling an e-mail address will be collected and used for spam. The following points are important when using address munging:
- Ensure the disguised version is not someone else's e-mail address. This can be done by appending the reserved top level domain .invalid to the end.
- If you are disguising an address by adding text to it, then add it to the right-hand side of the "@" not the left. This prevents your internet service provider's mail server from having to handle undeliverable mail.
Disadvantages
Disguising addresses makes it more difficult for people to send e-mail to each other and is, at best, a workaround for the problem of spam. When posting to usenet it should also be noted that disguising an email address is, in the strictest terms, a violation of RFC 1036. This RFC describes the format of usenet messages and requires a valid email address in the From: field of the post. In practise, few people follow this so strictly.
See also
External links
- Address Munging Frequently Asked Questions (http://www.faqs.org/faqs/net-abuse-faq/munging-address/)
- Article discussing why address munging is wrong (http://www.interhack.net/pubs/munging-harmful/)
- RFC 1036 — covers the format of Usenet posts
- http://address-protector.com/ Service to "encrypt" an e-mail-address, which can be "decrypted" by solving an image or audio Captcha