Validating the email address





-6
Date Submitted Tue. Feb. 28th, 2006 9:43 AM
Revision 1 of 1
Syntax Master dannyboy
Tags ASP | VBSCRIPT
Comments 5 comments
Validating the email address

Function IsValidEmail(emailAddress)
'Declare variables

Dim ValidEmail, emailParts, iLoopCounter, emailChar, acceptableChars
     ValidEmail = True '
set the default result to True

     'acceptableChars are the characters that we will allow in our email

     acceptableChars="abcdefghijklmnopqrstuvwxyz.-_@"
     '
use the Split function to create an array with the @ as the separator

     'so if your email was test@tester.com the email would be split into an array

     '
with the first array element holding "test" and the second "tester.com"

     emailParts = Split(emailAddress, "@")
     'check to make sure that there is only 1 @ and that there are 2 parts

     '
remember arrays are zero based

     'Using the UBound function will return the highest element in the array

     '
So if it's a valid email the UBound function will return 1, i.e. 0 start

     if UBound(emailParts) <> 1 Then
          ValidEmail = false
     Else
          '
Check the length of each part of the email address

          'first part can be just one character, 2nd part must be atleast 4

          if Len(emailParts(0))<1 OR Len(emailParts(1))<4 Then
               ValidEmail = false
          End If
          '
check first character on the left part isn't a "." using Left function

          if Left(emailParts(0), 1)="." Then
               ValidEmail = false
          End If
          '
check the last & 2nd character from right part using Right function

          if Right(emailParts(1), 1) = "." OR Right(emailParts(1), 2) = "." Then
               ValidEmail = false
          End If
          'check that there is a . in the second part of the email address - .com

          if InStr(emailParts(1), ".") <= 0 Then
               ValidEmail = false
          End if
          '
check that there shouldn't be a _ in the second part of the email address

          if InStr(emailParts(1), "_") >0 Then
               ValidEmail = false
          End if
     End If
          '
loop through each character of email

     For iLoopCounter = 1 to Len(emailAddress)
     'Use Lcase & Mid functions, Mid function used to return each individual character

     '
in the email, and then Lcase converts it into lowercase

     emailChar = Lcase(Mid(emailAddress, iLoopCounter, 1))
     'Check if the emailAddress characters are acceptable

          if InStr(acceptableChars, emailChar) = 0 and Not IsNumeric(emailChar) Then
               ValidEmail = false
          End if
     Next
     '
check if there is 2 . in a row

     if InStr(emailAddress, "..") > 0 Then
          ValidEmail=false
     End If
     'check if there is @. in a row

     if InStr(emailAddress, "@.") > 0 Then
          ValidEmail=false
     End if
     IsValidEmail=ValidEmail
End function
 

Comments

Comments double click on object
Fri. May. 27th, 2011 1:59 AM    Newbie kumar
Comments check valid mx record
Wed. Mar. 1st, 2006 5:56 AM    Syntax Master dannyboy
Comments check for valid domain
Wed. Mar. 1st, 2006 5:53 AM    Syntax Master dannyboy
Comments True
Wed. Mar. 1st, 2006 5:26 AM    Scripter TimYates
Comments Email validation scripts...
Wed. Mar. 1st, 2006 4:28 AM    Helper mercutio

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