Test and Newsletter Fails to Send Even Though it Looks Like It's Sending

Hi,
I tried to send a new newsletter and even though everything appears to be working, nothing gets sent (yes, I've checked my spam folders). My last newsletter sent on August 27, 2021 went off just fine and I've made no changes, except update all the plugins when they were due. I am using an email from my domain, not gmail or anything as the sender. I've contacted GoDaddy and they are stumped as am I. I've entered a support ticket as this is a timely Newsletter that was supposed to announce a new product - so this is a really, really bad time for a failure! Any suggestions appreciated. BTW, I do see these messages at the bottom of the test page:
[10] wpcf7_phpmailer_init
[100] NewsletterDefaultMailer::fix_mailer
Christie