When I mark several messages in my combined inbox and delete them, some of the messages are not deleted. I have multiple IMAP accounts and do not experience the problem in the inbox for the individual accounts, only for the combined inbox. Messages at the top of the list are deleted but at some point the remaining messages are not deleted. The account of the first non-deleted email is not the same each time. It does not matter if the messages selected for deletion are consecutive or consist of two or more blocks separated by unselected messages. It's not a critical problem but is a nuisance.