Option Explicit
Public EMsg As String 'used to return potential error messages in the functions below

Public Function ValidateEmail(ByVal strEmail As String) As Boolean
Dim strTmp As String, n As Long, sEXT As String
EMsg = "" 'reset on open for good form
ValidateEmail = True 'Assume true on init

sEXT = strEmail
Do While InStr(1, sEXT, ".") <> 0
   sEXT = Right(sEXT, Len(sEXT) - InStr(1, sEXT, "."))
Loop

If strEmail = "" Then
   ValidateEmail = False
   EMsg = EMsg & "<BR>You did not enter an email address!"
ElseIf InStr(1, strEmail, "@") = 0 Then
   ValidateEmail = False
   EMsg = EMsg & "<BR>Your email address does not contain an @ sign."
ElseIf InStr(1, strEmail, "@") = 1 Then
   ValidateEmail = False
   EMsg = EMsg & "<BR>Your @ sign can not be the first character in your email address!"
ElseIf InStr(1, strEmail, "@") = Len(strEmail) Then
   ValidateEmail = False
   EMsg = EMsg & "<BR>Your @sign can not be the last character in your email address!"
ElseIf EXTisOK(sEXT) = False Then
   ValidateEmail = False
   EMsg = EMsg & "<BR>Your email address is not carrying a valid ending!"
   EMsg = EMsg & "<BR>It must be one of the following..."
   EMsg = EMsg & "<BR>.com, .net, .gov, .org, .edu, .biz, .tv Or included country's assigned country code"
ElseIf Len(strEmail) < 6 Then
   ValidateEmail = False
   EMsg = EMsg & "<BR>Your email address is shorter than 6 characters which is impossible."
End If
strTmp = strEmail
Do While InStr(1, strTmp, "@") <> 0
   n = 1
   strTmp = Right(strTmp, Len(strTmp) - InStr(1, strTmp, "@"))
Loop
If n > 1 Then
   ValidateEmail = False 'found more than one @ sign
   EMsg = EMsg & "<BR>You have more than 1 @ sign in your email address"
End If
End Function


Public Function EXTisOK(ByVal sEXT As String) As Boolean
Dim EXT As String, X As Long
EXTisOK = False
If Left(sEXT, 1) <> "." Then sEXT = "." & sEXT
sEXT = UCase(sEXT) 'just to avoid errors
EXT = EXT & ".COM.EDU.GOV.NET.BIZ.ORG.TV"
EXT = EXT & ".AF.AL.DZ.As.AD.AO.AI.AQ.AG.AP.AR.AM.AW.AU.AT.AZ.BS.BH.BD.BB.BY"
EXT = EXT & ".BE.BZ.BJ.BM.BT.BO.BA.BW.BV.BR.IO.BN.BG.BF.MM.BI.KH.CM.CA.CV.KY"
EXT = EXT & ".CF.TD.CL.CN.CX.CC.CO.KM.CG.CD.CK.CR.CI.HR.CU.CY.CZ.DK.DJ.DM.DO"
EXT = EXT & ".TP.EC.EG.SV.GQ.ER.EE.ET.FK.FO.FJ.FI.CS.SU.FR.FX.GF.PF.TF.GA.GM.GE.DE"
EXT = EXT & ".GH.GI.GB.GR.GL.GD.GP.GU.GT.GN.GW.GY.HT.HM.HN.HK.HU.IS.IN.ID.IR.IQ"
EXT = EXT & ".IE.IL.IT.JM.JP.JO.KZ.KE.KI.KW.KG.LA.LV.LB.LS.LR.LY.LI.LT.LU.MO.MK.MG"
EXT = EXT & ".MW.MY.MV.ML.MT.MH.MQ.MR.MU.YT.MX.FM.MD.MC.MN.MS.MA.MZ.NA"
EXT = EXT & ".NR.NP.NL.AN.NT.NC.NZ.NI.NE.NG.NU.NF.KP.MP.NO.OM.PK.PW.PA.PG.PY"
EXT = EXT & ".PE.PH.PN.PL.PT.PR.QA.RE.RO.RU.RW.GS.SH.KN.LC.PM.ST.VC.SM.SA.SN.SC"
EXT = EXT & ".SL.SG.SK.SI.SB.SO.ZA.KR.ES.LK.SD.SR.SJ.SZ.SE.CH.SY.TJ.TW.TZ.TH.TG.TK"
EXT = EXT & ".TO.TT.TN.TR.TM.TC.TV.UG.UA.AE.UK.US.UY.UM.UZ.VU.VA.VE.VN.VG.VI"
EXT = EXT & ".WF.WS.EH.YE.YU.ZR.ZM.ZW"
EXT = UCase(EXT) 'just to avoid errors
If InStr(1, sEXT, EXT, vbBinaryCompare) <> 0 Then EXTisOK = True
End Function