hvad er der galdt med min mail sender til et nyhedsbrev

jeg for følgende fejl

jmail.SMTPMail error '8000ffff'

The message was undeliverable. All servers failed to receive the message

/Nyhedsbrev/mail_send.asp, line 55

scriptet ser således ud :

<%Dim afsender_mail, afsender_navn, mailserver, subject, body, priority, modtager_liste
afsender_mail = Trim(Request.Form("afsender_mail"))
afsender_navn = Trim(Request.Form("afsender_navn"))
mailserver = Trim(Request.Form("mailserver"))
subject = Trim(Request.Form("subject"))
body = Trim(Request.Form("body"))
priority = Request.Form("priority")
modtager_liste = Trim(Request.Form("modtager_liste"))
Response.Cookies("Nyhedsbrev")("afsender_mail") = afsender_mail
Response.Cookies("Nyhedsbrev")("afsender_navn") = afsender_navn
Response.Cookies("Nyhedsbrev")("mailserver") = mailserver
Response.Cookies("Nyhedsbrev")("subject") = subject
Response.Cookies("Nyhedsbrev")("modtager_liste") = modtager_liste
Response.Cookies("Nyhedsbrev").Expires = Date+365

Set mail = Server.CreateObject("JMail.SMTPMail") 'Opretter objekt af JMail-komponent
With mail
.ServerAddress = mailserver
.Sender = afsender_mail
.SenderName = afsender_navn
.Subject = subject
.Body = body
.Priority = priority

Set Conn = Server.CreateObject("ADODB.Connection")
DSN = "DRIVER={Microsoft Access Driver (*.mdb)}; "
DSN = DSN & "DBQ=" & Server.MapPath ("database.mdb")
Conn.Open DSN
Set rs = Conn.Execute("SELECT email FROM nyhedsbrev")
If Not rs.EOF Then
Do While Not rs.EOF
.AddRecipient(rs("email"))
Response.Write "Sender e-mail til: " & rs("email") & "<br />"
rs.MoveNext
Loop
Else
Response.Redirect("mail_write.asp")
End If
Conn.Close
Set Conn = Nothing
If modtager_liste <> "" Then
.HideRecipients = modtager_liste
End If
.Execute() 'Sender e-mails
mail.Close()
End With
Set mail = Nothing
Response.Write "<p>Færdig! - Nyhedsbrev sendt</p>"
%>