A mailbomb (or mail bomb), also called parcel bomb or letter bomb, is an explosive device sent via the postal service, and designed to explode when opened, injuring or killing the recipient, usually someone the sender has a personal grudge against, or more indiscriminately as part of a terrorist campaign. Some countries have agencies the job of which is in part the interdiction of mailbombs and the investigation of mailbombings.

Mail bombs are usually set to explode immediately on opening, with the intention of seriously injuring or killing the recipient (who may or may not be the person to which the bomb was addressed). Parcel bombs may have excessive postage because a bomber usually does not want to mail a parcel over the counter having to deal with a clerk. Letter bombs may feel rigid, or appear uneven or lopsided. Package bombs may have an irregular shape, soft spots, or bulges.

Bombs delivered by mail can often be recognised because they arrive in suspicious packages or unusual looking letters. The police and security consultants can advise how to recognise possible mailbombs.

Anyone suspecting that they have received a mail bomb is advised to:

• Lower the article to a level surface.
• Do not disturb the article. Do not open it or cut any strings.
• Do not place the article in a confined space. Do not immerse in water or cover the article.
• Do not permit anyone to touch or move the article. Leave it where it is.
• Clear the area immediately of all people. Evacuate the building.
• Leave doors and windows open, but do not linger to do this. This can reduce blast damage but it also provides a clear path for bomb disposal equipment.
• Do not operate mobile phones or portable radios until clear of the area, as these may trigger an explosive device if operated near by.
• Call the police once clear.

A related threat is mail containing unidentified powders or chemicals. In many cases, these turn out to be harmless, and often sent as a joke or hoax threat. However, until the substance can be analysed in a laboratory it may present a hazard, so police or environmental authorities may close the affected areas. This often is the intended purpose of the sender.

Emailbombing

In Internet usage, a mailbomb is a form of net abuse consisting of sending huge volumes of e-mail to an address in an attempt to overflow the mailbox or overwhelm the server. Mailbombing is sometimes accomplished by giving the victim's email address to multiple spammers.

At least in Russian Internet area there is one more sense for mailbomb. It states that mailbomb is a form of denial of service attack against a computer system (mail server). After the most of servers began checking the trespassing mail with anti-virus software, the trojan viri tried to send themselves compressed into archive, such as ZIP or RAR or 7-Zip. Then mailservers began to unpack archives and check their contents too. That gave script kiddies an idea to make a huge text file, containing, for example, the only letter 'Z' repeated millions of times. Such a file compresses in relatively small archive, but being unpacked by early versions of mail servers might waste the free space on its disks and cause denial of service.

See also

• Theodore Kaczynski, the Unabomber
• Franz Fuchs, Austrian mailbomb terrorist
• Johann Lang , German mailbomb terrorist
• Crank call
• Bomb threat

External links

• U.S. Postal Inspection Service - Mail bombs