I tried the suggested solutions and none worked. I was able to send emails until 5/22. Oddly, 3 emails sent after that including one test message 30 minutes ago, but I have several drafts that will not send. I just tried to send another test message to the same one I sent 30 minutes ago, and it wouldn't go. The test message was never received either. I have no problem receiving emails and I can send them if I sign onto the website, just not through Thunderbird.

I checked the settings and they all look right. Please see pictures for error message and settings. Thanks in advance!