I have used this pregmatch statement for validating email address
preg_match("^[a-z0-9_\+-]+(\.[a-z0-9_\+-]+)*@[a-z0-9-]+(\.[a-z0-9-]+)*\.([a-z]{2,4})$^", $partner_email)
If i use capital letters it will show an error.How i can change the pregmatch condition for supporting capital letters in email addres Thanks in advance