To stay productive sometimes I want to draft a message now to send later. It might be something to students. Or, I sometimes send a Zoom calendar announcement and want to send a traditional email reminder the day of the meeting. I used to use the Desktop app. This had one drawback in that it sometimes did not send if I did not have the desktop app open.
You can now do this from the web Outlook app. Draft your message. Click the down arrow next to the Send button inside the message. Select Send later and pick your date and time. The message will go to your drafts folder and will have red text above it showing when it will send.
Here is a video of me using the feature. It shows how straightforward it is.