Within the MAIL program, some of the new incoming mail is sent directly to "All mail" and not to "Incoming". Some mails do come in "Incoming". This is very inconvenient. Who knows what is the cause and how to fix it? I use macOS High Sierra 10.13.6.
iMac, macOS 10.13
Some people have inadvertently moved Inbox to All Mail or Archived, or Vice Versa, log into to your WebMail & see if you can find anything about it.
All mail includes what was filtered by your account so for example spam. Usually it's adverts that are filtered.
Thanks for your comment. This is not about spam. This is handled neatly. Even trusted mail sometimes often directly to 'All mail'.
Make any headway yet?
program Mail
