science

Non-Internet email address

Non-Internet email address is a science topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Non-Internet email address rather than just read about it. In short: A wide variety of non-Internet email address formats were used in early email systems before the ubiquity of the john.smith@example.com form used by Internet mail systems since the 1980s – and a few are still used in specialised contexts. Single system The earliest email addresses simply had to identify one user from another on one homogenous system, often a single host minicomputer or mainframe.

Key takeaways

Non-Internet email address belongs to science; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Non-Internet email address to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Non-Internet email address from memory before moving on to harder problems.

Reference excerpt

A wide variety of non-Internet email address formats were used in early email systems before the ubiquity of the john.smith@example.com form used by Internet mail systems since the 1980s – and a few are still used in specialised contexts.

Single system The earliest email addresses simply had to identify one user from another on one homogenous system, often a single host minicomputer or mainframe. They were therefore typically the user's login name on that system. Examples of this style include:

ATS: 123 CompuServe: 432654,6564 MCI Mail: 373-1994 AOL: Steve Case

At a host As computer systems became networked email addresses needed to be able to identify not only the user, but also which host or mail system they were on. Addresses of this type were used in a number of early email systems, including:

ARPANET: jim@washington IBM Network Job Entry (NJE) TSO/E TRANSMIT: user_id, node.user_id, node/user_id, nickname, distribution list name, (addressee,...) VM SENDFILE: userid, userid AT YOURNODE, userid AT node, nickname PROFS: userid@node DECnet: host::user (e.g. DECWRL::WRL-TECHREPORTS) cc:Mail: John Alexopoulos at MicroCircuits MHS: Barry@MICROSOFT

Delivery path

Some email address schemes described the path through multiple hosts needed to deliver email. This worked well only if the first host given in the path was sufficiently well known for the sender's system to be able to contact it.

UUCP "bang path": reed!percival!bucket!lisag

Hierarchical Hierarchical addressing schemes are naturally able to expand. The modern Internet email address (e.g. john.smith@example.com), is of this type – but it was also used by a number of early systems, including:

Banyan VINES: Ed Hirsch@Faculty@Univ Grey Book: USERID@UK.AC.CAM.ENG FidoNET: lenz @ 2:331/113.1 Lotus Notes: Tyler Hamilton/Sales@Europe

Directory systems In this type of system, there is no one unique address for a specific user, but instead a series of attributes, not all of which may be needed to identify the user. For convenience however, there may be recommended formats for sharing on business cards and similar contexts, such as:

X.400: C=no;ADMD= ;PRMD=uninett;O=sintef;OU=delab;S=Alvestrand;G=Harald

See also Email address History of email Reverse domain name notation Protocol Wars

Notes

References

Worked examples

Example 1 — a first encounter with Non-Internet email address

Start with the simplest possible case. Write down what Non-Internet email address claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In science, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Non-Internet email address before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Non-Internet email address ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Non-Internet email address

In research: Non-Internet email address appears in science research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Non-Internet email address in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Non-Internet email address is common in secondary-school and first-year university syllabi. It links to neighbouring topics Email, so understanding it makes those chapters shorter.
In everyday life: Look for Non-Internet email address outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

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How to study Non-Internet email address in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Non-Internet email address means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Non-Internet email address out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Non-Internet email address in simple terms?

Why does Non-Internet email address matter?

Because it connects several science ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Non-Internet email address?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Non-Internet email address.