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An Email Validation Script
By Ben Durbin


Here is yet another great server-side email validation routine. The code is in text format via a link at the bottom.

function chkEmail(theAddress)
   ' checks for a vaild email
   ' returns 1 for invalid addresses
   ' returns 0 for valid addresses
   dim atCnt
   chkEmail = 0

   ' chk length
   if len(theAddress) < 5  then 
      ' a@b.c should be the shortest an
      ' address could be
      chkEmail = 1
 
   ' chk format
   ' has at least one "@"
   elseif instr(theAddress,"@") = 0 then
      chkEmail = 1
 
   ' has at least one "."
   elseif instr(theAddress,".") = 0 then
      chkEmail = 1
 
   ' has no more than 3 chars after last "."
   elseif len(theAddress) - instrrev(theAddress,".") > 3 then
      chkEmail = 1
 
   ' has no "_" after the "@"
   elseif instr(theAddress,"_") <> 0 and _
       instrrev(theAddress,"_") > instrrev(theAddress,"@")  then
      chkEmail = 1

   else
      ' has only one "@"
      atCnt = 0
      for i = 1 to len(theAddress)
         if  mid(theAddress,i,1) = "@" then
            atCnt = atCnt + 1
         end if
      next
 
      if atCnt > 1 then
         chkEmail = 1
      end if

      ' chk each char for validity
      for i = 1 to len(theAddress)
        if  not isnumeric(mid(theAddress,i,1)) and _
		(lcase(mid(theAddress,i,1)) < "a" or _
		lcase(mid(theAddress,i,1)) > "z") and _
		mid(theAddress,i,1) <> "_" and _
		mid(theAddress,i,1) <> "." and _
		mid(theAddress,i,1) <> "@" and _
		mid(theAddress,i,1) <> "+" and _
		mid(theAddress,i,1) <> "-" then
            chkEmail = 1
        end if
      next
  end if
end function

Attachments:

  • Code in Text Format

    Happy Programming!


  • Article Information
    Article Title: Server-side Email Validation
    Article Author: Ben Durbin
    Published Date: Wednesday, May 19, 1999
    Article URL: http://www.4GuysFromRolla.com/webtech/051999-1.shtml


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