Send mail using Redemption (RDO)

I am using Redemption ( RDO

) to send an email. The mailing list works very well, but when mail is received in Outlook, the yellow envelope remains closed. Typically, you click on an unopened email and then change the icon from a yellow closed envelope to a white open envelope. When I send an email with the help RDO

, the envelope remains yellow and closed.

How can I suppress that the envelope is open?

Here is my code:

RDOSessionClass rdoSession = new RDOSessionClass();
rdoSession.LogonExchangeMailbox("username", "server");

// Create mail object and send mail
RDOMailClass m = (RDOMailClass)rdoSession.GetSharedDefaultFolder("user", rdoDefaultFolders.olFolderInbox).Items.Add("IPM.Mail");
m.Recipients.Add(_mail.Recipient);
m.Recipients.ResolveAll(null, null);
m.Subject = _mail.Subject;
m.Body = _mail.Body;
m.SenderEmailAddress = "email@address.domain";
m.Send();