missing scheduled send later mails in the sent folder

How can I check that a send later scheduled mail has actually been sent?

I have started using the send later feature on my apple mails. I schedule a mail to be sent on a later date. I can see the mail in the "send later" folder i.e. all looks okay.

I ensure my macbook is up and running and the internet is available at the time the mail should be sent.

(Although I expect anyway that the mail should still be sent as soon as I boot up my macbook or make internet available should that be the case). In this case the internet is available and the macbook is running at the schedule send time.

When I check after the scheduled date and time I can see that the scheduled mail is no longer in the "send later" folder. So it appears as if it has been sent. However I cannot see the mail in the "sent" folder. Why? Is there somewhere else I should be looking? Is the mail really sent?

Please help. Thanks.

I am using a Macbook pro 13" M1 2020 and MacOs Ventura 13.0.1.