Office Watch
 
       
Check out the past issues!
Email Essentials

EMAIL Essentials

Office BACKUP Handbook our guide to keeping your docs and emails safe. Subscriber special, save $5.
1 August 2006 - Vol. 4 No. 15
 

>>>  Recover damaged Microsoft Works files at http://ref.OfficeRecovery.com/works/?wmf <<<
Got unreadable Works document, spreadsheet or database? Try Recovery for Works! Three great utilities available both standalone and as a convenient suite. Easy to set up and use. Free demo available.
*** Click http://ref.OfficeRecovery.com/works/?wmf ***

Ads make Office Watch possible, please support our sponsors How to advertise click here

@ What can you put in your email address?

A simple question – what characters can you put in an email address?   Like many things to do with the Internet the answer isn’t as simple or direct as you might think.

In this issue we’ll look at what makes a valid email address, both in theory and in practice.

For daily use you don’t need to know.  If you simply copy the email address as you’re given it, you should be OK.

But knowing a bit more about email addressing can help you work out if an email address is incorrect or identify why it doesn’t work.   Developers and programmers might be surprised to discover that their carefully written web pages or code aren’t entirely correct.

Organizing Outlook Email

Organizing Outlook Email is a practical guide to taming the messages that arrive in your Inbox with step-by-step instructions and tips from people who've used Outlook since 1996.

There are all sorts of features in Outlook (Outlook 2003, Outlook 2002 (XP) and Outlook 2000) to help you arrange your email, some obvious, others not so obvious. We'll take you through all the choices with examples and plenty of color images to illustrate (important because we talk about colored flags etc).  Then we'll show you how to get Outlook to do some of that arranging for you.  Outlook Rules are very powerful and you'll be able to harness that power with our step-by-step examples. 

It's the first of our 'Quickie' guides - short ebooks on a focused and practical topic, available at a low price.   Organizing Outlook Email is over 45 pages long with color images, step-by-step instructions, searchable and re-sizable text (easier to read but only US$4.95 for Email Essentials readers).

While the price is low we're keeping our usual subscribers discount for all Email Essentials readers giving you a discount on the retail price. Go to http://shop.office-watch.com/ooe/FastTrack.asp .

Google Checkout
If you'd like to try the latest service from Google, you can use Google Checkout for buying Organizing Outlook Email

New!  Our ebooks are available from AMAZON.

You can add 'Eye-catching Signs with Word', 'Organizing Outlook Email' and 'Office Backup Handbook' to your normal Amazon shopping cart and pay with most Amazon payment methods.  Only retail (non-subscriber) pricing is available via Amazon. Click here

@ Which ones are correct?

Which of these email address (all fake) is formatted correctly?

f.r.e.d.a.g.g@gmail.com

"Frederick Dagg"@freddagg.com

Fred+sheepdip@freddagg.com

Fred*Dagg=funny@freddagg.com

FredO’Dagg@freddagg.com

Bruce^Bayliss@freddagg.com

Prof~Taihape@freddagg.com

FD{Prof}@freddagg.com

Pa$toral@freddagg.com

The answer is that they are all strictly valid though they might not be useable in practice.

Knowing a bit more about email addresses may well interested many readers of ‘Email Essentials’ who, like us, get intrigued by these details. In keeping with the ‘Essentials’ part of our name, this is by no means a comprehensive look at email address formatting. We’ve provided links to the various RFC specification documents if you’re interested in the minutiae.

@ Local Address @ Domain

There are two parts to an email address – the ‘Local Part’ and the Domain – which are separated by the famous @ symbol.

For example  fred@freddagg.com  has ‘fred’ as the local part and ‘freddagg.com’ as the domain.

Historical note: back at the start of the internet, Ray Tomlinson developed the first simple email system to work between computers.  He’s the guy who chose the @ symbol to separate the name and domain name.

The two parts of an email address have different rules about what is permitted. Domains are much more limited than local parts.

@ Domain rules

A domain name can contain letters, digits and hyphens only, up to a maximum of 255 characters.

Each part of a domain name is separated by the . (aka dot, fullstop or period).

Domain naming is a whole article on its own – suffice it to say what we’re used to domains like .com .edu etc but there are also country domain suffixes (Top Level Domains TLD’s) like .au  .uk and .us right down to obscure ones like .hm (for the usually uninhabited Heard and McDonald Islands).  See http://www.iana.org/cctld/cctld-whois.htm for a full list.

There’s no consistency about domain suffixes.  The commercial domain name is a good example.  In the US it’s .com as we all know. Australia clones that for .com.au but the UK uses .co.uk  and New Zealand follows suit with .co.nz .

That’s pretty straight-forward, the surprises come when you look at the part before the @ symbol …

@ Local Part rules

Back in 1982 an Internet standard for email addresses was formalized called “Standard for the format of ARPA Internet text messages” which goes under the catchy name of RFC 822 and it’s this standard that most email systems obey.

There was an update to that in April 2001 called ‘Internet Message Format’ known as RFC 2822 .

According to RFC 2822 the local part of an email address can contain any of the following characters.

  • A to Z letters, upper and lower case.
  • 0 through 9 digits
  • . (fullstop, period) but not as the first or last character
  • ! # $ % & ' * + - / = ? ^ _ ` { | } ~ - all are permitted.

It’s this last point which might surprise some people – most might think that an email address using one of these non-alphanumeric characters is ‘illegal’ but it’s not.  That said, it’s quite possible that one of these ‘extra’ characters will not be accepted by a system. 

Other characters (including spaces) are also permitted if included within double quote marks.  For example   Bruce Bayliss@freddagg.com  is not permitted but  “Bruce Bayliss”@freddagg.com is permitted (though it might not be accepted by a lot of software and is definitely NOT recommended).

An email address might be ‘legal’ but that doesn’t necessarily mean that software will accept it.  We’re not just talking about email software – email addresses are often used as identification or login so those systems should check and accept the full range of valid characters.   As we were preparing this issue we noticed that Microsoft Word did not recognize all the sample email addresses as such.

Shame file: this article was prompted, in part, when we discovered our own online store wasn’t properly configured. It turns out that the store code we purchased didn’t comply with RFC 2822, though it’s taken 18 months or more to strike an email address which broke the system.  And yes, our programmers are working on a fix as I type this.

Even Google’s Gmail doesn’t fully obey the email specification in one important way.  A period  ‘.’ can be used within a local part and it won’t change the mailbox destination. For example  fre.dagg@gmail.com  fred.agg@gmail.com and even f.r.e.d.a.g.g@gmail.com will all arrive at the mailbox of fredagg@gmail.com . This is unlike almost any other mail system which would consider each of those addresses to be quite different.

The plus sign +  is a special case and can be used for tricky purposes on some email systems. We’ll cover that in a future issue.

Outlook add-ins save time and help you be more productive:
* New! Mobile Email Redirect - get your Outlook email on your mobile
* Vcard Converter - easily transfer contacts to your iPod and back
* Auto Print - automatically print incoming emails and attachments
* Now with 32 Outlook add-ins

Ads make Office Watch possible, please support our sponsors How to advertise click here

@ Length of an email address

The local part can be up to 64 characters, much less than the domain part at 255 characters

That means the maximum email address length is Local Part plus @ plus domain or 64 + 1 + 255 = 320 characters.

An email address of anything approaching 320 characters is rare, but it probably will come as an unwelcome surprise to programmers who have assumed a much shorter length in their databases. 

Even the standard maximum 255 character text field isn’t sufficient, in theory. We looked at an Access sample database from Microsoft which only allows 50 characters in total for an email field.

As with many things about Internet specifications, there’s a gap between what is permitted and what is supported.  Shorter email addresses are better for various reasons but developers might want to consider accommodating longer strings (for structural convenience probably 255 characters).

@ UPPER or lower case

According to RFC 2821 (the related SMTP specification), email addresses should be case-sensitive (ie FRED@ , Fred@ and fred@ are three different email prefixes). 

However, even the specification notes that this is to be discouraged. In practice email addresses should be case INsensitive – thought there are rare cases when some receiving systems make the case distinction (usually this is a programming oversight).

@ Use what works

All these suggestions, rules and RFC’s are all well and good but as we’ve seen there is no firm laws that everyone has to obey.    There’s no point setting up an email address which some people won’t be able to use.

Talk Email

We love to hear from our readers. Feel free to write to us with your experiences, questions, gripes and loves about all things email. Send mail to talkemail@office-watch.com - All messages are kept confidential.  We regret that the volume of mail and the limit of 24 hours in each day mean that, much as we'd love to, we cannot reply to individual messages.


Email Essentials

Editor-in-Chief: Peter Deegan

Copyright (c) 2006 Office Watch. All rights reserved. ISSN 1448-8655

Advertising:  Advertising is available at reasonable rates ask Jan, our Advertising Manager for detail.

bar
Office WatchAccess WatchEmail EssentialsOffice for Mere Mortals,  and all titles used within the publications are
Copyright © 1996-2008 Peter Deegan.
Website maintained by Calmer Software Services  |  Contact Webmaster
Sitemap |  Helpdesk |  Privacy Statement |  Advertising |  FAQs