Mail (Mac Ventura) content of folders does not track email shown in web page on Safari browser
In the Safari browser on my iMac, I can see long list of emails I have generated and sent.
In Apple Mail on my iMac the sent folder is empty, even after ordering rebuild the mailbox.
In Apple Mail on my iPhone 13, the sent folder matches what the browser shows, not what Apple Mail on my iMac. (2019, Ventura)
This problem applies to many other folders in Apple Mail on the iMac but the solution to the Sent folder will probably help with the other folders.
The only plug-in is SpamSieve which is updated to 3.0. The problem I think was happening prior to upgrading SpamSieve.
iMac 27″, macOS 13.5