Sending Emails with BCC list not working

Question

I am trying to send emails to a single 'To' recipient, and a list of 'Bcc' recipients. The list of Bcc recipients is a list of string, and they are successfully being added to the mailMessage's Bcc collection, but not actually being sent. If I add the same list to the message's 'Cc' collection it works fine. Just not the Bcc collection. The code I'm using is this:

 public void SendEmailMessage(String FromAddress, String ToAddress, String Subject, String Body, List<String> CCAddress, List<String> BccAddress, String Filepath)
    {
        using (SmtpClient mailClient = new SmtpClient())
        {
            MailMessage mailMessage = new MailMessage();
            mailMessage.From = new MailAddress(FromAddress);
            mailMessage.To.Add(new MailAddress(ToAddress));
            foreach (String _email in CCAddress)
            {
                mailMessage.CC.Add(new MailAddress(_email));
            }
            foreach (String _email in BccAddress)
            {
                mailMessage.Bcc.Add(new MailAddress(_email));
            }
            mailMessage.Priority = MailPriority.Normal;
            mailMessage.Subject = Subject;
            if (Filepath != string.Empty)
            {
                Attachment _attachment = new Attachment(Filepath, MediaTypeNames.Application.Octet);
                mailMessage.Attachments.Add(_attachment);
            }
            AlternateView plainTextView = AlternateView.CreateAlternateViewFromString(GetTextonly(Body), null, "text/plain");
            AlternateView htmlView = AlternateView.CreateAlternateViewFromString(Body, null, "text/html");
            mailMessage.AlternateViews.Add(plainTextView);
            mailMessage.AlternateViews.Add(htmlView);
            SmtpClient smtpClient = new System.Net.Mail.SmtpClient();
            smtpClient.Send(mailMessage);
        }
    }

any ideas?

Answer 1

one thing i didn't mention is that the mail is put in a pickup directory rather than sent direct. I found a blog which explains that bcc addresses aren't sent if using a pickup directory, and you can put them in the retry directory instead. This solved my problem with an easy fix: Unable to send Bcc using System.Net.Mail when specifying a Pickup Directory(Exchange 2007/Exchange 2010) in code