To avoid sending an email to the wrong recipient, you can set up an automatic delay on outgoing email messages. This will give you a short period of time where you can go to your outbox folder and cancel/delete the message before it is sent.
To Setup an Automatic Delay
1. Go to outlook.office.com and log into your email account
2. Click the gear icon in the top right corner
3. Scroll down the Settings Menu and Click "Mail"
4. Under Mail > Automatic processing > Undo send, select the option to "Let me cancel the messages I've sent for" and select the amount of time you want the messages to be delayed in the dropdown box
5. Click Save