I have successfully being using the Limilabs IMAP .Net component for several months now. Today I updated my code to support BCC addresses. My code is basically this:
string theBCC = "email@example.com";
builder.Bcc.Add(new MailBox(theBCC, ""));
This code runs fine, but the when I view the draft of the email in GMail, there is no value for Bcc. My To: and Cc: fields work just fine.