EMails fail to send

I have had so many emails that could not send today that I am ready to go back to Thunderbird. I have run diagnostics and all seems fine, yet the emails do not get sent. Frustrated!

Click the drop down arrow on tbe right of refresh top left and click Show Operations. Then click the Log tab and look for any obvious error messages. Then paste them in this thread. Blank out any personal info.

I am now no longer using EM Client, I’ve gone back to Thunderbird.
It is working.
Bob