Cdo email not delivering the messages

Public ErrorStrMail As Variant
Dim oMail As CDO.Message
Dim oConf As CDO.Configuration
Dim FileSize
Dim SumSize
Dim oFlds
Dim oFSO
Dim oFile
Dim sFolder
Dim oFolder
Dim user
Private SMTPSrvr As String
Private SMTPPrt As Integer
Private Sndusing As Integer

Property Let SMTPServer(text As String)
    SMTPSrvr = text
End Property

Property Let SMTPPort(valu As Integer)
    SMTPPrt = valu
End Property

Property Let SendUsing(valu2 As Integer)
    Sndusing = valu2
End Property

Public Function SendMail(toAddr, whoAddr, docSubj, docMsg, ByVal docType As Integer, Optional cc = "", Optional bcc = "", Optional sFolder = "", Optional user = "")
    On Error GoTo MailErr
    Set oFlds = oConf.Fields
    oFlds(cdoSendUsingMethod) = Sndusing
    oFlds(cdoSMTPServer) = SMTPSrvr
    oFlds(cdoSMTPServerPort) = SMTPPrt
    oFlds(cdoSMTPAuthenticate) = cdoBasic
    oFlds.Update
    Set oMail = New CDO.Message
    oMail.From = whoAddr
    oMail.To = toAddr
    If (cc <> "") Then
        oMail.cc = cc
        If (bcc <> "") Then
            oMail.bcc = bcc
            If oFSO.FolderExists(sFolder) Then
               Set oFolder = oFSO.GetFolder(sFolder)
                  For Each oFile In oFolder.Files
                      If InStr(oFile.Name, "_" & user) > 0 Then
                                     oMail.AddAttachment oFile.Path
                                     FileSize = Format((FileLen(oFile) / 1024) / 1024)
                                     SumSize = SumSize + FileSize
                                     oFSO.DeleteFile (oFile)
                      End If
                  Next
            End If
        End If
    End If
    If ((docType Mod 2) = 0) Then
        oMail.TextBody = docMsg
        Else:
        oMail.HTMLBody = docMsg
    End If
    If (SumSize > 10) Then
       ErrorStrMail = "Attachment size too large!"
       GoTo MailFlee
    End If
    oMail.Subject = docSubj
    Set oMail.Configuration = oConf
    oMail.Send
MailFlee:
    Exit Function
MailErr:
    ErrorStrMail = Err.Number & ":" & Err.Description
    Resume MailFlee
End Function

Private Sub Class_Initialize()
    Set oFSO = CreateObject("Scripting.FileSystemObject")
    Set oConf = New CDO.Configuration
    Set oFlds = oConf.Fields
    FileSize = 0
    SumSize = 0
    oFlds(cdoSendUsingMethod) = Sndusing
    oFlds(cdoSMTPServer) = SMTPSrvr
    oFlds(cdoSMTPServerPort) = SMTPPrt
    oFlds(cdoSMTPAuthenticate) = cdoBasic
    oFlds.Update
End Sub