sent emails don't appear in sent mailbox
Yesterday I sent three emails but they don't appear in my sent mailbox. I only use iCloud. I have tried all the other places (drafts, recovered mail etc) but there's nothing there. I am using Catalina 10.15.7. The messages don't appear on my iPad or iPhone either. Can anyone suggest what might have happened and whether I can retrieve these rather important messages sent my accountant! Thanks
Katharine’s 27" iMac, iMac 27″