Delay send and stuck emails in Outlook
I used delayed emails in Outlook
https://support.microsoft.com/en-us/office/delay-or-schedule-sending-email-messages-026af69f-c287-490a-a72f-6c65793744ba
Often, messages get stuck in my outbox, and these tricks helped:
https://www.howto-outlook.com/faq/messagestuckinoutbox.htm