Knowledge Base

Message recall/revoke in Outlook & CodeTwo Email Signatures for Office 365

Problem:

You would like to know if CodeTwo Email Signatures for Office 365 supports message recall/replace capability in Outlook desktop apps (Fig.1.) and email revocation for messages protected with Office 365 Message Encryption (OME).

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Fig. 1. The message recall option is available in Outlook's Sent Items.

Solution:

Yes, both the message recall feature in Outlook and the ability to revoke encrypted emails work with CodeTwo Email Signatures for Office 365 on board.

Recalling messages in Outlook desktop apps

Regardless of the CodeTwo software, the message recall functionality in Outlook seems to cause problems for some users and does not always function as they expect. To increase the chance for Outlook's message recall to work correctly, the following conditions need to be met:

  • Both the recipient and the sender need to belong to the same Exchange organization.
  • Both the recipient and the sender need to use Outlook. If the recipient uses Outlook on the web (OWA) or a mobile Outlook client when the message is delivered, then message recall will not work.
  • The message needs to be delivered to the recipient's Inbox. Message recall does not work if the recipient has an Outlook rule that redirects emails to another folder.
  • The message cannot be marked as read before the message recall is done by the sender:
    • If the recipient is reading the message at the moment, then as long as the message subject remains in bold letters (which is typical if you read the email in the same window, without popping it out), Outlook treats it as unread and the recall will work (even though the sender may have already read the message).
    • If the message is already marked as read when you do the recall, the recall fails. Marking the email as unread (Mark as Unread) in Outlook will not make the message recall work.

If you are sure all the above conditions are met but you still experience problems with the message recall functionality in Outlook, please contact our Support Team.

For more information on the functioning and limitations of Outlook's message recall, see this Microsoft article.

Revoking emails protected with Office 365 Message Encryption

No matter if CodeTwo Email Signatures for Office 365 adds signatures server-side (after an email is sent) or client-side (directly in Outlook when you type a message), email revocation works well. However, keep in mind that:

  • Email revocation works only with messages encrypted using Office 365 Advanced Message Encryption.
  • You can only revoke messages sent to recipients that don't use an Office 365 or Microsoft 365 email account, or Outlook.com account. In other words, email revocation works only if your recipient (e.g. a Gmail or Yahoo! user) gets a link to the OME Portal, where they can read your message. 
  • The revoke feature works differently than recall. The revoked message is not removed from recipients' mailboxes. Recipients simply can no longer access the revoked message via a link.
  • For your users to add client-side signatures and then be able to revoke them, they need to use the modern CodeTwo Signatures Web Add-in for Outlook in Outlook on the web (OWA).
  • In server-side mode, messages need to be encrypted after emails are routed through the CodeTwo Email Azure Service to get a signature.

Use the following links to a Microsoft article to learn how to:

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