E-mail address validation

Is there a way to set up a field where there's validation that the format is
a valid email address? For example, I have any number of characters before
the @ symbol then any number of characters before the . symbol then three
characters. Does that make sense? Any help would be really great! Thanks
in advance.
Tracy

On Mon, 7 Sep 2009 20:57:01 -0700, TBell506
wrote:

Is there a way to set up a field where there's validation that the format is
a valid email address? For example, I have any number of characters before
the @ symbol then any number of characters before the . symbol then three
characters. Does that make sense? Any help would be really great! Thanks
in advance.
Tracy

What makes you think that's the only valid email addresses possible?



would be a perfectly valid address. So would



This isn't a trivial problem at all!
--

John W. Vinson [MVP]

Simplest approach would be to open your table in design view, and add a
validation rule on the field.

Something like this:
Is Null OR ((Like "*?@?*.?*") AND (Not Like "*[ ,;]*"))
where you put the invalid characters inside the square brackets.

For an explanation of validation rules, see:
http://allenbrowne.com/ValidationRule.html

--
Allen Browne - Microsoft MVP. Perth, Western Australia
Tips for Access users - http://allenbrowne.com/tips.html
Reply to group, rather than allenbrowne at mvps dot org.


"TBell506" wrote in message
...
Is there a way to set up a field where there's validation that the format
is
a valid email address? For example, I have any number of characters
before
the @ symbol then any number of characters before the . symbol then three
characters. Does that make sense? Any help would be really great!
Thanks
in advance.
Tracy

=?Utf-8?B?VEJlbGw1MDY=?= wrote
in :

Is there a way to set up a field where there's validation that the
format is a valid email address? For example, I have any number
of characters before the @ symbol then any number of characters
before the . symbol then three characters. Does that make sense?
Any help would be really great! Thanks in advance.

I've cribbed this Regular Expression from others. I use it in the
email scripts on my web pages:

^[_a-z0-9-]+(\.[_a-z0-9-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)+$

This informative, pragmatic and sensible article:

http://www.regular-expressions.info/email.html

....considers the subject and the drawbacks of various approaches. It
even offers the RegEx that is supposed to implement the exact RFC
for valid email addresses. Here it is:

(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|"(
?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b
\x0c\x0e-\x7f])*")@(??:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](
?:[a-z0-9-]*[a-z0-9])?|\[(??:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\
..){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]?:[\
x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e
-\x7f])+)\])

Wisely, that article recommends *not* using this RegEx.

--
David W. Fenton http://www.dfenton.com/
usenet at dfenton dot com http://www.dfenton.com/DFA/

On 8 Sep 2009 18:10:04 GMT, "David W. Fenton"
wrote:

It
even offers the RegEx that is supposed to implement the exact RFC
for valid email addresses. Here it is:

(?:[a-z0-9!#$%&'*+/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+/=?^_`{|}~-]+)*|"(
?:[\x01-\x08\x0b\x0c\x0e-\x1f\x21\x23-\x5b\x5d-\x7f]|\\[\x01-\x09\x0b
\x0c\x0e-\x7f])*")@(??:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](
?:[a-z0-9-]*[a-z0-9])?|\[(??:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\
.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?|[a-z0-9-]*[a-z0-9]?:[\
x01-\x08\x0b\x0c\x0e-\x1f\x21-\x5a\x53-\x7f]|\\[\x01-\x09\x0b\x0c\x0e
-\x7f])+)\])

Wisely, that article recommends *not* using this RegEx.

Thanks, David!

As I said: not trivial!
--

John W. Vinson [MVP]