Disposition-Notification-To

[Ed Lukoski]

I'm trying to send mail (via our Exchange v5.5 server) from a VB.Net
webapp and get Delivery Notification and Read Receipt. If I use

mail.Headers.Add("Return-Receipt-To", "ma*****@whatever.com")

I can get a delivery notification to work - but so what? That only
(apparently) means that the mail server accepted it and tossed it into
the user's mailbox. I want to use

mail.Headers.Add("Disposition-Notification-To",
"ma*****@whatever.com")

to notify me that someone has actually read the message, but it isn't
working. I can generate an email from Outlook and get the receipt,
but from my program, it doesn't work :(

Anybody got a clue for me?

<code snippet>
mail.From = sUserUserID & "@whatever.com"
mail.To = sSupervisorUserID & "@whatever.com"
'mail.Cc = sManagerUserID & "@whatever.com"
mail.Subject = "Annual Evaluation For " & sEEFullName & " in " & sUnit
mail.BodyFormat = MailFormat.Html
mail.Body = sMailBody
' delivery notify
mail.Headers.Add("Return-Receipt-To", "[e-mail]")
'read notify
mail.Headers.Add("Disposition-Notification-To", "[e-mail]")
SmtpMail.SmtpServer = "mail.whatever.com"
SmtpMail.Send(mail)
</code snippet>