Regular expression for some email rules

Question

I used a regular expression for email formats, which I thought was fine, but the client complains that the expression is too strict. Therefore, they returned with the following requirement:

The email must contain the character "@" and end with either .xx or .xxx, i.e. (. nl or .com). They are happy with this to pass the test. I started the expression to see if the string contains the "@" symbol below

^ (? =. * [@])

it seems to work, but how to add the last requirement (should end in .xx or .xxx)?

Answer 1

A regex just fulfilling your two requirements:

^.+@.+\.[a-zA-Z]{2,3}$

, , .

Answer 2

          ^([a-zA-Z0-9_\-\.]+)@((\[[0-9]{1,3}" +
            @"\.[0-9]{1,3}\.[0-9]{1,3}\.)|(([a-zA-Z0-9\-]+\" +
            @".)+))([a-zA-Z]{2,4}|[0-9]{1,3})(\]?)$

http://www.ultrapico.com/Expresso.htm!

Answer 3

RegEx, . , - , :

[^@]+@.+\.\w{2,3}$

:

• [^ @] +: , @
• @: @
• . +:
• \: a.
• \w {2,3}: 2 3 - (a-zA-Z)
• $:

Answer 4

:

([\w-\.]+)@((?:[\w]+\.)+)([a-zA-Z]{2,4})\be(\w*)s\b

A good tool to test our regular expression: http://gskinner.com/RegExr/

Answer 5

you can use

[@].+\.[a-z0-9]{2,3}$

Answer 6

This should work:

^[^@\r\n\s]+[^.@]@[^.@][^@\r\n\s]+\.(\w){2,}$

I tested it against these invalid emails:

@[e-mail]   
example@domaincom  
exampledomain.com  
exampledomain@.com  
exampledomain.@com  
example.domain@.@com  

e.x+a.1m.5e@em.a.i.l.c.o  

[e-mail].c  
some-user@[e-mail]  
some-user@@internal-email.company.co  

@test.com  
test@asdaf  
test@.com    
[e-mail]  

And these are valid letters:

[e-mail]  
[e-mail]  
[e-mail] 

change

This seems to confirm all the addresses from this wikipedia page, although it probably also allows the use of some invalid emails. The brackets will be broken into everything before and after @:

^([^\r\n]+)@([^\r\n]+\.?\w{2,})$

[e-mail]
[e-mail]
[e-mail]
[e-mail]
[e-mail]
user@[IPv6:2001:db8:1ff::a0b:dbd0]
"much.more unusual"@example.com
"very.unusual.@.unusual.com"@example.com
"very.(),:;<>[]\".VERY.\"very@\\ \"very\".unusual"@strange.example.com
postbox@com
admin@mailserver1
 !#$%&'*+-/=?^_`{}|~@example.org
"()<>[]:,;@\\\"!#$%&'*+-/=?^_`{}| ~.a"@example.org
" "@example.org
üñîçøðé@example.com
üñîçøðé@üñîçøðé.com