[Rets-dev] Email validation regular expression

[Matt Lavallee]

Alright, here we go:
^(?:[\w\!\#\$\%\&\'\*\+\-\/\=\?\^\`\{\|\}\~]+\.)*[\w\!\#\$\%\&\'\*\+\-\/\=\?\^\`
\{\|\}(\\\@)\~]+@(?:(?:(?:[a-zA-Z0-9](?:[a-zA-Z0-9\-](?!\.)){0,61}[a-zA-Z0-9]?\.
)+[a-zA-Z0-9](?:[a-zA-Z0-9\-](?!$)){0,61}[a-zA-Z0-9]?)|(?:\[(?:(?:[01]?\d{1,2}|2
[0-4]\d|25[0-5])\.){3}(?:[01]?\d{1,2}|2[0-4]\d|25[0-5])\]))$

I think that's ugly enough. ;)

-Matt

> -----Original Message-----
> From: Paul Stusiak [mailto:pstusiak at falcontechnologies.com]
> Sent: Wednesday, April 25, 2007 4:07 PM
> To: Matt Lavallee
> Cc: rets-dev at rets.org
> Subject: Re: [Rets-dev] Email validation regular expression
> 
> Thank you for the suggestion.
> 
> Your suggestion does not validate the following valid email addresses:
> 
> !def!xyz%abc at local.example.com
> a.one_two{}@some.example.com
> a.one_two at some.example.com
> some\@one at example.com
> 
> which was tested using the on-line regex testing tool
> http://www.fileformat.info/tool/regex.htm
> 
> A good location for regular expressions is here
> http://regexlib.com/
> 
> search for email. There is grading (use with caution, the results don't
> always match the grade...)
> 
> This is where the root of the regex came from that is in the Phone.xsd.
> I've also seen regular expressions that enumerate the possible top level
> domains - this strikes me as a bad thing for a standard since the
> addition of new top level domains which happens on a regular basis,
> would require a change to the schema.
> 
> Also note that xsd do not use the '^' and '$' to indicate the start and
> end of line.
> 
> As noted in the schema, the patterned used does not cover all cases, but
> does cover the first three above but not the some\@one at example.com
> pattern where reserved characters are escaped. It didn't seem necessary
> to me.
> 
> On the full expression, I have seen something similar to this and I
> agree with you that it is overkill.
> 
> For the interested, the relevant RFCs are 2822 and 3696.
> 
> Matt Lavallee wrote:
> >
> > Mostly for Paul’s edification, this will pick up all RFC-compliant
> > email addresses:
> >
> > ^[-!#$%&'*+/0-9=?A-Z^_a-z{|}~](\.?[-!#$%&'*+/0-9=?A-Z^_a-z{|}~])*
> >
> > @[a-zA-Z](-?[a-zA-Z0-9])*(\.[a-zA-Z](-?[a-zA-Z0-9])*)+$
> >
> > And, just for kicks, I also found the /fully/-compliant expression:
> >
> > (?:(?:\r\n)?[ \t])*(?:(?:(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:
> >
> > (?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.
> >
> > |(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t]
> >
> > )*(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=
> >
> > [\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(
> >
> > ?:(?:\r\n)?[ \t])*))*@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \
> >
> > x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\
> >
> > [([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])
> >
> > *(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[
> >
> > \["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*
> >
> > ))*|(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(
> >
> > ?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*
> >
> > "(?:(?:\r\n)?[ \t])*)*\<(?:(?:\r\n)?[ \t])*(?:@(?:[^()<>@,;:\\".
> >
> > \[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\
> >
> > ]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?
> >
> > [ \t])*(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\
> >
> > Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[
> >
> > \t])*))*(?:,@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \x00-\x1F
> >
> > ]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]
> >
> > \r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()
> >
> > <>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@
> >
> > ,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*)*:(?
> >
> > :(?:\r\n)?[ \t])*)?(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\
> >
> > n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?
> >
> > :\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[
> >
> > ^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()
> >
> > <>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\
> >
> > r\n)?[ \t])*))*@(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \x00-\x
> >
> > 1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[
> >
> > \]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^
> >
> > ()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<
> >
> > >@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*\>(
> >
> > ?:(?:\r\n)?[ \t])*)|(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r
> >
> > \n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(
> >
> > ?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)*:(?:(?:\r\n)?[ \t])*(?:(?:
> >
> > (?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\
> >
> > ["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:
> >
> > (?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \
> >
> > x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"
> >
> > (?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*))*@(?:
> >
> > (?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?
> >
> > [ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(
> >
> > ?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \x
> >
> > 00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[
> >
> > ([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*|(?:[^()<>@,;:\\".\[\]
> >
> > \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))
> >
> > |"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)*\<(
> >
> > ?:(?:\r\n)?[ \t])*(?:@(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:
> >
> > \r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*
> >
> > \](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\
> >
> > [\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]
> >
> > ]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*(?:,@(?:(?:\r\n)
> >
> > ?[ \t])*(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|
> >
> > \Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?
> >
> > [ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \x00-\x1F]
> >
> > +(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\
> >
> > r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*)*:(?:(?:\r\n)?[ \t])*)?(?:[^(
> >
> > )<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>
> >
> > @,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\
> >
> > n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \x00-\x
> >
> > 1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?:[^\
> >
> > "\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*))*@(?:(?:\r\
> >
> > n)?[ \t])*(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])
> >
> > +|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n
> >
> > )?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \x00-\x1
> >
> > F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\
> >
> > ]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*\>(?:(?:\r\n)?[ \t])*)(?:,\s
> >
> > *(?:(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(
> >
> > ?=[\["()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*
> >
> > "(?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[
> >
> > \] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]
> >
> > ))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*))*
> >
> > @(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r
> >
> > \n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\]
> >
> > (?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\
> >
> > ] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]])
> >
> > )|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*|(?:[^()<>@,;:\\".
> >
> > \[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\
> >
> > ]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*)
> >
> > *\<(?:(?:\r\n)?[ \t])*(?:@(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?
> >
> > :(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\
> >
> > \.)*\](?:(?:\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\
> >
> > \".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".
> >
> > \[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*(?:,@(?:(?:\
> >
> > r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t
> >
> > ])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:\r
> >
> > \n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \x00-\
> >
> > x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\
> >
> > [\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*)*:(?:(?:\r\n)?[ \t])*)?(?
> >
> > :[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["
> >
> > ()<>@,;:\\".\[\]]))|"(?:[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?
> >
> > :\r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \x0
> >
> > 0-\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|"(?
> >
> > :[^\"\r\\]|\\.|(?:(?:\r\n)?[ \t]))*"(?:(?:\r\n)?[ \t])*))*@(?:(?
> >
> > :\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \x00-\x1F]+(?:(?:(?:\r\n)?[
> >
> > \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([^\[\]\r\\]|\\.)*\](?:(?:
> >
> > \r\n)?[ \t])*)(?:\.(?:(?:\r\n)?[ \t])*(?:[^()<>@,;:\\".\[\] \x00
> >
> > -\x1F]+(?:(?:(?:\r\n)?[ \t])+|\Z|(?=[\["()<>@,;:\\".\[\]]))|\[([
> >
> > ^\[\]\r\\]|\\.)*\](?:(?:\r\n)?[ \t])*))*\>(?:(?:\r\n)?[ \t])*))*
> >
> > )?;\s*)
> >
> > -Matt
> >
> > pmpt_logo
> >
> > PMPTechnology.com <http://www.pmptechnology.com/>
> >
> >
> >
> > *Matt Lavallee*
> > /Manager of Web Services/
> >
> > /phone:/ 630-598-2301
> > /fax:/ 630-982-6641
> >
> > ------------------------------------------------------------------------
> >
> > _______________________________________________
> > Rets-dev mailing list
> > Rets-dev at rets.org
> > http://lists.rets.org/mailman/listinfo/rets-dev
> >
> 
> --
> Paul Stusiak
> Falcon Technologies Corp.