Slow system.net.mail performance?

[Fabuloussites]

I've made small class to sent email using the system.net.mail namespace and
it is really slow. any ideas why i'm having such a performance hit?

it seems to work much better when i don't use authentication, however, it's
very slow when i do use it.

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Imports Microsoft.Visua lBasic
Imports System.Net
Imports System.Net.Mail

Public Class emailhelper
Sub sendmail(ByVal emailto As String, ByVal emailfrom As String, ByVal
emailfromname As String, ByVal body As String, ByVal subject As String)
Dim Msg As MailMessage = New MailMessage()
Dim MailObj As New
SmtpClient(Conf igurationManage r.AppSettings(" SmtpServer"))
MailObj.UseDefa ultCredentials = False
MailObj.Credent ials = New
Net.NetworkCred ential("em***** ****@test.com", "password")
MailObj.Deliver yMethod = SmtpDeliveryMet hod.Network

Msg.From = New MailAddress(ema ilfrom, emailfromname)
Msg.To.Add(New MailAddress(ema ilto))
Msg.IsBodyHtml = "True"
Msg.Body = body
Msg.Subject = subject
MailObj.Send(Ms g)

End Sub
End Class