Unable to send emails from Apple Mail on iMac after Sequoia upgrade

Since upgrading to Sequoia I can no longer send e-mail. When I try to send an email it goes the draft folder and will not send. I can go to my iPhone and send it from my draft folder but I can't send it from my iMac. What do I need to change?

[Re-Titled by Moderator]

Original Title: Apple mail does not allow me to send mail on my iMac since upgrading to Sequoia. When I try to send it goes unsent to my draft mailbox