Imbabi said:
How do I block message recall in Outlook?
There is no option within Outlook to disable its decode of the
message-ID header in trying to perform a recall action.
Recall rarely works across different e-mail servers. It only sometimes
works when both sender and recipient are using the same Exchange server
(or Exchange servers within the same organization); however, you are
sending e-mails via SMTP, not Exchange. That means rather than issuing
a recall *function* to the Exchange server to yank out the original
e-mail from the recipient's mailbox, you are sending a *new* e-mail that
requests the recipient's mail client to remove an item AFTER the mail
client has downloaded the original message from their mailbox. That
means the mail client must understand the header in your 2nd new e-mail
that makes the recall request. It also requires that the recipient open
the recall e-mail BEFORE they open your original message - and that
means the recipient would need to have mails listed in descending sort
order rather than ascending sort order. If the recipient opens your
original mail (which they WILL already have downloaded) before opening
your recall mail then they can obviously read the original message
because they have not first opened your recall mail to then attempt to
delete the original message. Even if the recipients read their mails in
descending sort order, it is unlikely that their mail client knows how
to handle a recall. The Microsoft-specific non-standard modification of
the Message-ID header (by adding the "!-!" prefix and encoding
instructions within the domain portion of the message ID) is used to
indicate a recall but it is only recognized by users of Outlook (and
they have to read e-mails in descending order to open your recall mail
first) so don't expect the recall to work. A recipient using anything
other than Outlook 2000+, like Outlook Express, will see both the
original message and recall message and opening the recall first will
NOT delete the original message. Non-Outlook e-mail clients don't know
how to handle the encoded recall request.
If using Exchange to send your e-mails and they are to a recipient using
the same Exchange organization then recall might work because the mail
server is handling the request to delete messages from the recipient's
mailbox. That is not your case. You are using SMTP from your e-mail
provider to the SMTP host of another e-mail provider. Recall won't work
unless both sender and recipient use Outlook 2000+ and the recipient
happens to open the recall message first. Getting a recall mail will
only draw more attention by the recipient to your original message.
http://support.microsoft.com/kb/197094/en-us
If you read the help already included in Outlook to search on "recall",
it would have plainly stated "This feature requires Microsoft Exchange".
For SMTP, there is a very, VERY, V-E-R-Y slim possibility that if the
recipient also uses Outlook that the recall via Message-ID directive
will work since Outlook used to handle that method. It rarely works.