Email is not a modern technology; it infact predates the age/boom of the Internet: ARPANET was converted to the Internet in the early 1980s, the Internet boom began in the early 1990's. It is difficult to pinpoint the exact date email was born, some experts believe the CTSS mail system developed by MIT in the 1960s was the genesis of email.
What is certain, is that ARPANET computer network - the precursor to the Internet - featured a mail service in the early 1970s, and that this mail technology was standardised in RFC_733: located at http://tools.ietf.org/html/rfc733. The "@" symbol was first used in ARPANET mail: this innovation was the brainchild of Ray Tomlinson; a US citizen and computer programmer, he is is generally recognised as being the first person to send an email.
The problem with ARPANET and LAN based mail services in the 1970s and 1980s was making them compatible with one another. Request For Comments memorandums have attempted to outline and revise the format for text messages across APRANET and the Internet. The following RFC memorandums are an evolution of this process, each making the previous memorandum obsolete.