You wish to know whether Exclaimer Cloud supports the message recall feature in Microsoft Outlook or you have encountered an issue with message recalls working correctly.
Yes, Exclaimer Cloud supports the use of the message recall feature; however, there are some limitations you should be aware of:
- Message recall utilizes a Messaging Application Programming Interface (MAPI) property named SearchKey to correctly identify the message in the recipient's mailbox.
Microsoft Exchange uses the SearchKey property for multiple purposes and is likely to change if the email is routed via a connector. In this scenario, the message recall is unlikely to succeed as it will be unable to determine the correct message to be recalled.
Exclaimer has confirmed with Microsoft that they are unable to alter this behaviour. As Exclaimer Cloud and many other vendors' server-side solutions use connectors, we recommend using client-side signatures in organizations where the message recall feature is essential.
To maximise your chances of message recall functioning where emails are sent via connectors, please ensure that your Remote domains settings are configured to Use rich-text format (TNEF enabled) for your internal domains. For further information, please see Transport Neutral Encapsulation Format (TNEF).
- Message recall requires both the sender and the recipient to have a Microsoft 365 or Microsoft Exchange email account in the same organization. This means that the recall message will not work if you send emails externally, for example, to your customers or personal email accounts like Gmail, Yahoo and so on.
- If the recipient has already read the email message, the recall will not work as intended. In this case, the recipient will be notified that the sender wanted to recall the message.
- Both the recall message and the email to be recalled must exist in the same folder in the recipient's mailbox.
- You cannot recall a message that's protected by Azure Information Protection.
For more information, see Microsoft's documentation on message recall.