Hello Carol,
Hope you are doing well. Thank you for reaching out to the Microsoft community.
According to the description, when you recall an email in Outlook, if you receive the error message "Mismatch between the original message sent time and recall message sent time," it means that there is a mismatch between the time when the original message was sent and the time when the recall message was sent. This error can occur if there is a delay in sending the recall message or if the original message has already been read by the recipient before the recall message arrives. Unfortunately, this error indicates that the recall attempt was not successful.
If you're using the Microsoft Outlook app or Outlook.com, and if you and your recipients are all on Microsoft Exchange or Microsoft 365****and in the same organization, you can recall or replace an email message that you sent.
To recall email message from new outlook/classic outlook, kindly follow the mention below link for navigation.
Link: Recall or replace an email message that you sent in Outlook - Microsoft Support
If any other information is required regarding this, kindly inform us. Your patience and cooperation are much appreciated.
Sincerely
Nafis Iqbal Shuvo