Since the update to 10.0.3447 (d250ce6) my gmail accounts no longer appear in all inboxes. They don’t even appear in the gmail inboxes but are only found in the all mail category for each of my 3 gmail accounts. I basically want to turn off all categories and have all my mail from all my accounts appear in the all inboxes. I’ve tried to fix this in settings but could not get the gmails to appear in the all inboxes category.
Did you try turning Categories off?
Settings > Mail > Categories then untick Show categories
Then click Apply or Save & Close
See if that resolves the issue.
Yes, that fixed it! Thanks very much. 
