check for valid email

as a start, try look for:
http://regexr.com/3bcrb

you can go to Community tab and search for other available email regular expressions.

or you can try this:
http://www.regular-expressions.info/email.html

There's no one regular expression that can detect whether any given email is valid.  There are too many possible forms and too many possibilities.

Example 1:  Non-ASCII domain names will cause simple regular expressions to fail.  [A-Za-z0-9] is not enough to contain all the possibilities of Chinese or Middle Eastern sites.

Example 2:  It's perfectly valid for an email address to be of the form xyz@alpha.beta.gamma.delta.epsilon.somewhere.com, which "violates" the common "a@b.c.com" format.

Example 3:  There are non-standard exceptions to the general "a@b.c.com" format.  Consider exex!research!ucbvax!user@ketch-ai, a valid uucp address.

In the final analysis, the only way to know if an email address is valid is to send to that address.

What would be a minimum check?
 How can I check if it contains
name (1)   - john
@ (2)  
(3)domain -   yahoo.com
and check if @ comes between the name and the domain, but not like yahoo.com@john

I use the format of 'a@b.c'.  There are no single letter user names or domain names that I know of.  I did run into one user with a 2 letter user name.  I don't use Regex though.

1. split the name at @.  If there is no @, it is not valid.
2. the first part before the '@' must be greater than 1 character.  It can contain '.'.
3. split the second part after the '@' on '.'.
4. each part of the second part must be greater than 1 character.  There are some TLDs like 'tv' that are only 2 letters.

it lacks support for stuff like "foo bar"@mydomain.com
anyway, given the fact the author has been gone for 2 months without feedback...

Thank you very much for your help. Sorry for late reply.

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