Dear MichaelV_123,
Good day!
Thank you for posting to Microsoft Community. We are happy to assist you.
Typically, when you use a delayed email in Outlook, recipients will see the "not to deliver before" time you selected. Because the email message that you compose and schedule to send will remain in the Outbox folder until the scheduled time arrives. Then Outlook will send this email, and the email will leave your server and delivered to the recipient at the scheduled time. As a result, the recipient will see the timestamp of the scheduled time (the timestamp you filled in in the "not to deliver before" section) instead of the timestamp you hit the send button. I have been testing your query from y end, you can refer to the test and result screenshot below.
Test From sender side
Test #1 scheduled email to send on 3:00 AM and send.
Test #2 the scheduled email in Outbox folder at 2:57 AM
Result recipient side: The recipient received the email on the scheduled time 3:01 AM instead of 2:57 AM where I originally send 2:57 AM.
Result sender side:
Therefore, based on our test results, we can confirm that your recipients will not know that you are working outside normal business hours since scheduled emails are sent to them during business hours.
We look forward to you update. Please feel free to let me know if there are any questions or if we've got you wrong. We will keep assisting you based on the information you provide. We sincerely appreciate your patience and cooperation.
Stay safe and healthy.
Have a good day!
Sincerely,
Libeamlak | Microsoft Community Moderator