The Science Behind Emails

Just like any ordinary letter, every e-mail has a sender address and recipient address. For e-mail, these take the form ‘myname@mydomain.domain.mycountry’, where ‘mycountry’ stands for actual countries (.au, .jp, .fr, .uk, etc.), ‘domain’ stands for a class of organisations (.org), networks (.net), individuals (.name), government bodies (.gov) or educational institutions (.edu), among others.

The ‘mydomain’ part may be the name of your company. When an e-mail is sent, it is divided into several data packages, which are numbered and dispatched through the widely branching network. This ensures that the message arrives, even when lines or servers are defective.

Every computer involved in the process leaves a kind of stamp on the e-mail, so it is possible to reconstruct the route. The target computer does not announce an e-mail until all its parts have arrived and been put together again.

Where does the @ sign come from?

The ‘at’ sign probably originated in the Middle Ages; either as an abbreviation of the Latin ‘ad’ (at, towards, by) or as a mercantile abbreviation for ‘amphora’. The symbol has endured to this day in Spain, Portugal and France, as the unit of weight ‘arroba’, which is equal to about 15 litres or 10 kg.

It also occurs in old German legal texts, while in English-speaking countries it served as an assignment of price (5 eggs @ 20 cents).

From these distant beginnings, the symbol made its way onto typewriter keyboards, where it waited to be chosen by the author of the world’s first e-mail when he was looking for an address component. In 1971, Ray Tomlinson needed a sign that could be found on all common keyboards but wasn’t a letter of the alphabet.

With the @ sign he managed to provide an unambiguous separator between the two parts of an e-mail address.