Brian said:
Is there any way to "undo" sending a message in Outlook if it hasn't
been read by the recipient yet?
No. So be careful from now on about what you write.
If you send an e-mail using Exchange as your mail server and it is to a
recipient within that same Exchange organization then you can try to
recall the message. It is not reliable.
If you send an e-mail using SMTP then you can attempt to recall the
message. Outlook does this by sending out yet another message to the
same recipient. This reply has a special header to identify the prior
e-mail message. If the recipient also uses Outlook then this reply
message might get honored; otherwise, it will look like yet another
e-mail from you. The recipient must open your reply (to recall the
prior message) *BEFORE* they open your original message. That is, they
would have to read your latest message before they read your earlier
message. Even if the recipient gets your specially coded recall message
and even if they use Outlook and even if they read the recall message
before reading your previously sent message, it is still a flaky
feature.
In short, recall rarely works under the conditions where it is supposed
to work. Those conditions are so restrictive that the procedure is
doomed to fail. Do a search in Outlook's own help on "recall" if you
want to know how to use it.
