Outlook Desktop Delay Delivery When Laptop Off/Closed

Dear CarlXQ,

Good day! Thank you for posting to Microsoft Community.

I understand your concern about the delay delivery feature in Outlook Desktop. The delay delivery feature in Outlook Desktop still requires the computer to be on and connected to the internet for the emails to be sent at the scheduled time. This is because the emails are stored locally in the Outbox and need the Outlook client to be running to process and send them. Also, the official article still has the warning and since you are using classic outlook, you can select classic to refer this information. Delay or schedule sending email messages in Outlook - Microsoft Support

However, if you are using Exchange online account and want to schedule delay delivery even if your laptop is off or in sleep mode.  You may try to run your outlook in online mode as a workaround below:

Typically, When Outlook is running in Cached Exchange Mode, it uses a local offline folder file (.ost). This file is periodically synchronized with the server. When you enable the Do not deliver before option to defer the delivery of a message, the message is deferred to the local Outbox, not to the server. Therefore, the message will not be delivered from the local .ost file unless Outlook is running when the message is scheduled to be delivered. 

Therefore, when you use online mode, the deferred messages are submitted to the Exchange message queue and held until the scheduled time as Outlook doesn’t have a local cache when you use online mode, so it can’t hold them at the client. This only works if you have the account set up in Outlook in online mode. It will not work with Outlook.com accounts, IMAP and POP as they do not support online mode.

By default, Outlook sets Exchange accounts up in cached mode. Therefore, to turn off this cached mode and turn on Online mode, Go to File --> Account Settings --> Account Settings --> under Email tab, Select your email --> Change -->untick Use Cached Exchange Mode to download email to an Outlook data file to drop to online mode --> Next --> Done. Restart your Outlook. You can refer to the screenshot below.

Before, the status bar shows 'Connected to: Microsoft Exchange', when you have cached mode turned on(ticked)

After, the status bar should say 'Online with: Microsoft Exchange', when you have cached mode turned off.,

Note: Before you disable cached mode: if you have the messages already in the Outbox (already scheduled emails) move them to Drafts folder first so they will sync to the server. After you switch to online mode, go to the Drafts folder and Sendthe messages. You won't see the messages if you look in Outlook on the web, so you just have to trust Exchange. To verify it is working, create an email to email address you can check on your phone. Defer it for 15 min from now and click Send. Close Outlook. If you receive the message in 15 min, it’s set up properly.

We look forward to you update. Please feel free to let me know if there are any questions. 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

You are welcome.

If you have any more questions or need further assistance, please feel free to let me know and if incase my above reply helps to clarify the issue, could you please help to vote or submit feedback on my reply? it helps other user who are searching for the same information. Thanks for your support and understanding.

For other questions, feel free to add your post in the Microsoft Community team.

Thank you for your precious time. Have a nice day! 

Sincerely,

Libeamlak | Microsoft Community Moderator

Thank you so much! I had not appreciated the need to flick between New and Classic support page tabs (though clearly it's right there in writing!). Thank you for the answer and for providing a workaround as well - really handy.