Email recall is a Microsoft Outlook feature that allows senders to attempt the removal of a message from a recipient's mailbox after it has been sent. This capability is not guaranteed and is subject to several limitations, especially when mail is routed through connectors or processed by third-party providers. While Opensense applies email signatures seamlessly, message recall is generally incompatible with server-side processing methods and should not be relied upon.
How Email Recall Works
Email recall in Microsoft Outlook allows users to retract or replace an email message that has already been sent.
Key Points:
Eligibility:
Both sender and recipient must be using Microsoft 365 or Microsoft Exchange accounts within the same organization.
The recipient must be using Outlook and have it open when the recall is attempted.
The message must still be unread by the recipient for the recall to succeed.
Options Available:
Recall the Message: Delete the original email from the recipient’s inbox.
Replace the Message: Delete the original email and substitute it with a corrected version.
Important Limitations:
If the message has already been read, it cannot be recalled.
If the recipient’s Outlook settings (like rules or additional mailbox configurations) interfere, the recall may fail.
External recipients (outside your organization) cannot have messages recalled.
Mobile apps and web-based versions of Outlook do not support initiating a recall.
Technical Limitations
Message recall leverages the SearchKey MAPI property to identify the message within the recipient's mailbox. When messages are routed through connectors (as is common with server-side solutions), the SearchKey may be altered, rendering the recall ineffective.
Microsoft has confirmed that this behavior is a limitation of using connectors to route mail to third-party services. This applies broadly to all server-side solutions, including Opensense.
Summary
Email recall is a legacy Microsoft feature with limited reliability, especially in modern cloud environments or when using server-side email enhancements.
For more information, refer to Microsoft’s documentation on email recall:
Exchange Online Message Recall limitations – Microsoft Learn
MAPI SearchKey Property – Microsoft Developer Docs