how do I retract a sent email

For some email providers you can setup the account up to be able to retract a messsge but only for a short window. You can setup Gmail to have 30 seconds after sending to retract the message

https://gilsmethod.com/retract-messages-gmail

You can't.

tt2

Is the email Server is an Exchange Server one might be able.

Otherwise - what is done is done.