[TYPO3-dev] Re: RFC: #11301: Feature: add eval email

[bernd wilke]

Am Wed, 27 May 2009 17:12:08 +0200 schrieb Mathias Schreiber [wmdb >] in 
typo3.teams.core:

> Steffen Kamper schrieb:
>> Hi,
>> 
>> Johannes Feustel schrieb:
>>> evalFunc_email doesn't test if a tld exists. Why not using RegExp like
>>> /^([\w]+)(\.[\w]+)*@([\w\-]+\.){1,5}([A-Za-z]){2,4}$/; (copied from
>>> ExtJS) or using ExtJS validation directly?
>>>
>>>
>> i didn't want to run in same problems we had before in php with reg
>> exp., so JS-test is very simple:
>> does @ exist, does . exist, don't start with @, don't end with . The
>> deeper validation is done php-side.
> 
> I like the idea, the docs should clearly state that the validation is
> rather basic and that email like huselpusel at 192.168.13.13 aren't covered
> by this.

if the validation should be complete you need a much complexer regexp, as 
email-addresses could be much more complex [1].
on first look: meanwhile there is a TLD 'museum': your last counting 
{2,4} must be expanded, but than you got other problems: [2]
second thought: what about umlaut-domains? "fritz at müller.de" (I don't 
think they are handled by [1])

I think a full regexp will be slow, either javascript or PHP, and a real 
validation will have to test wether the server exists and accepts mail 
for this address. And then you won't know wether there will be a reader 
to this mail or if it is dropped as unwanted. 
Two weeks ago I got a huge load of undelivery-mails as a result of a spam-
wave with sender-addresses with random addresses from my domain (probably 
combining real address parts in front of '@' with my domain). There were 
a lot of 'valid' email-addresses but no mailbox to receive them 

[1] http://www.ex-parrot.com/~pdw/Mail-RFC822-Address.html
[2] http://www.regular-expressions.info/email.html

bernd

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