
My Sent messages have disappeared
In Thunderbird, the content of all my Sent emails has disappeared. When I went to my Sent folder, the sent emails were listed but when I clicked on any of the listed emails, the body was blank. I right-clicked the Sent folder, selected Properties and then clicked Repair Folder. My Sent folder now lists messages that I sent today and yesterday and I can see the content of those emails... but none of the previous Sent emails are listed.
My email history is essential to my business. Unfortunately, I never figured out how to back up the Thunderbird file incrementally so I don't have a backup. Is there any way that I can recover my Thunderbird Sent emails?
P.S. If my Thunderbird Sent email history is unrecoverable, then I think I need to find a different email client that I can back up incrementally... or should I switch to directly using Outlook online in my Microsoft 365?