This certainly works for receivers with Outlook Express also. But it might be that some webmail (as used by Yahoo) doesn't support it. Webmail is behaving differently from pop3-mail, and programmed by your ISP as he wants.
You can easily this check yourself by sending a message to
(a) yourself (home address maybe) and read it with Outlook Express
(b) opening a free hotmail-account and sending a message to that
(c) install a different pop3-client like Thunderbird (or find somebody who uses that) and send a message to it
Hope this helps.
Kees
We are using Outlook 2003. I'm interested in info on requests for read receipts. I always knew that you could send a read receipt request to anyone on your network; but I have now started receiving read receipt requests from email coming from outside of my office. The lightbulb went off in my head (DUH) that read receipts are not limited to my network users.
I attempted to send a request for read receipt to two outside email addresses: One user uses Outlook at a work domain and the other was a Yahoo address (no Outlook interface). The Outlook user received and responsed to my read receipt request. The Yahoo user did not even receive the request. I was able to get a delivery receipt to the Yahoo address; just not the read receipt.
Can I assume that the "catch" to a read receipt request is that the recipient has to be using Outlook?
Thanks in advance.

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