用ASP判斷Email地址是否有效
2000-03-23· 王俊·CPCW

在用ASP編寫頁面時，如果涉及到郵件發送，一般會要求輸入Email地址。錯誤的Email地址往往帶來許多不必要的麻煩，用下面的函數IsValidEmail就能判斷出一個Email地址是否有效。
函數源代碼：
<%
Function IsValidEmail(Email)
ValidFlag = False
If (Email <> "") And (InStr(1, Email, "@") > 0) And (InStr(1, Email, ".") > 0) Then
atCount = 0
SpecialFlag = False
For atLoop = 1 To Len(Email)
atChr = Mid(Email, atLoop, 1)
If atChr = "@" Then atCount = atCount + 1
If (atChr >= Chr(32)) And (atChr <= Chr(44)) Then SpecialFlag = True
If (atChr = Chr(47)) Or (atChr = Chr(96)) Or (atChr >= Chr(123)) Then SpecialFlag = True
If (atChr >= Chr(58)) And (atChr <= Chr(63)) Then SpecialFlag = True
If (atChr >= Chr(91)) And (atChr <= Chr(94)) Then SpecialFlag = True
Next
If (atCount = 1) And (SpecialFlag = False) Then
BadFlag = False
tAry1 = Split(Email, "@")
UserName = tAry1(0)
DomainName = tAry1(1)
If (UserName = "") Or (DomainName = "") Then BadFlag = True
If Mid(DomainName, 1, 1) = "." then BadFlag = True
If Mid(DomainName, Len(DomainName), 1) = "." then BadFlag = True
ValidFlag = True
End If
End If
If BadFlag = True Then ValidFlag = False
IsValidEmail = ValidFlag
End Function
%>
用法舉例：
IsValidEmail("my_263_email@263.net") 返回Ture
IsValidEmail("zh99wj@tonghua.com.cn") 返回Ture
IsValidEmail("myemail263.net") 返回False
IsValidEmail("my_263_email@263) 返回False
請注意，函數只是判斷Email地址格式是否有效，但并不能檢查該地址是否確實存在。（出處：熱點網絡）