#include <StringConstants.au3> ; to declare the Constants of StringRegExp
#include <Array.au3> ; UDF needed for _ArrayDisplay and _ArrayConcatenate
Local $sRegex = "(?m)[a-z0-9._%+-]+@[a-z0-9.-]+\.[a-z]{2,4}$"
Local $sString = "// Allowed" & @CRLF & _
"one@a.com" & @CRLF & _
"one.two@ab.com" & @CRLF & _
"one.two@abc.ab" & @CRLF & _
"one.two@abc.abc" & @CRLF & _
"one.two@abc.abcd" & @CRLF & _
"a1_b2@abc.abc" & @CRLF & _
"a1b2@ab-cd.abc" & @CRLF & _
"a1b2@abcd.ab.cd" & @CRLF & _
"" & @CRLF & _
"// Not allowed " & @CRLF & _
"one.two@abc.a" & @CRLF & _
"one.two@abc.abcde" & @CRLF & _
"one.two@abc.12" & @CRLF & _
"" & @CRLF & _
""
Local $aArray = StringRegExp($sString, $sRegex, $STR_REGEXPARRAYGLOBALFULLMATCH)
Local $aFullArray[0]
For $i = 0 To UBound($aArray) -1
_ArrayConcatenate($aFullArray, $aArray[$i])
Next
$aArray = $aFullArray
; Present the entire match result
_ArrayDisplay($aArray, "Result")
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for AutoIt, please visit: https://www.autoitscript.com/autoit3/docs/functions/StringRegExp.htm