Problem with smtp read receipts

Dec 21, 2016 at 11:59 AM

Using your SMTP (HigLabo.Mail.dll ver, I have a problem with Read receipts, the sender doesn't receive this mail. I use these code lines for to send the request:

mailMsg = New HigLabo.Net.Smtp.SmtpMessage
mailMsg.Headers.Add(New HigLabo.Net.Smtp.SmtpMailHeader("Return-Receipt-To", "")) For information I'm sure that server manage this request, because using standard .NET Framework library (System.Net.Mail) with the property DeliveryNotificationOptions=DeliveryNotificationOptions.OnSuccess, it works, while if use header "Return-Receipt-To" also this don't works.

Can you help me please ?