SMTP mail service not working

It may be something to do with the MailFormat, try setting it as below. I have pasted all the code I use in a class that works fine. I declare oMessage the same as you but at the top of my class. oMessage.To = m_sAn; oMessage.From = m_sVon; if(m_mfEmail!=MailFormat.Text && m_mfEmail!=MailFormat.Html) m_mfEmail = MailFormat.Text; oMessage.BodyFormat = m_mfEmail; oMessage.Bcc = m_sBcc; oMessage.Cc = m_sCc; oMessage.Subject = m_sBetreff; oMessage.Body = m_sText; oMessage.Priority = m_mpWichtig; //oMessage.Fields.Add(); SmtpMail.SmtpServer = m_sServer; SmtpMail.Send(oMessage);