sent emails vanish

I use Apple Mail in Mac OS 13.5.2, This evening, my sent email began vanishing. I send them, I get the "woosh" sound, but they never reach the recipient and never appear in my sent mail. They are also not in drafts or outbox. I have tried with three accounts -- two gmail and an iCloud--and they all have the same problem. My internet is working great.

I went to gmail on the web and sent an email with no problem--and THAT email appeared in my Apple Mail sent mailbox.

I've tried quitting and reopening the app several times and poked around in settings but nothing seems different--I have not made any changes to this setup in a long time. Any ideas?