Outlook: can't delete messages moved to root folder by a rule

I made a mistake configuring rules to move incoming emails to another email account (both IMAP). As the target I did't specify 'Inbox' but instead the target email account itself, i.e. the parent folder of 'Inbox'. These mails are not shown in 'Inbox', but only when I click on the account's email address. Now I corrected these rules to move future incoming mails to the correct 'Inbox' of the target account.

My problem is that I don't have rights in the root folder to delete the mails that have already been moved there. I was able to mark them and copy them to the 'Inbox', but I could't move them there or delete them. When right mouse clicking on this root folder, the option to modify rights is grayed out / disabled.

I am using Outlook 365 on Windows 10 Pro.

Based on my test of my Gmail account on my outlook 365 client, I reproduced your isuue. However, I did a lot of tests and did not find a way to delete these messages directly. When I add this account in the new profile, these messages will not be displayed after I click on the account's email address. As a workaround, it’s suggested that you could create a new profile(File > Office Account > About Outlook) and add your accounts to see if there're any differences.

Of course, I'm glad your problem has been solved. Please mark your own reply as the answer, so that people with the same questions in the forum can get help.