Dear Information4
Welcome to Microsoft Community.
I understand that you are having trouble on delete multiple mail from inbox.
Since I don't know which version of Outlook you are using, I will provide you with the solutions for deleting emails in batches in the three current versions of Outlook.
By holding down the Shift key on the keyboard and clicking with the mouse, you can quickly go from the first selected email to the second selected email.
After successfully selecting, it will appear in the selected state as shown in the picture below. At this time, click the Delete key on the keyboard or the Delete button on the screen to delete them.
Of course, we have other ways to select emails, such as if you want to select one email at a time.
Press and hold the Ctrl key and use the mouse to select the emails, confirm the selection and delete them.
If you want to select all emails to delete, press Ctrl+A on the keyboard to select all emails and delete them.
The above deletion method will move the emails to the Deleted Items folder. If you want to permanently delete these emails at once, select the emails you want to delete and press Shift+Delete to permanently delete them.
Pay attention to distinguish between Focused sectors and Other sectors.
The methods are universal. I have captured three pictures below for you, showing the operation process of multi-select deletion in Outlook web version, Outlook (new), and classic Outlook. I hope it can help you.
The website below also provides specific steps for deleting emails for your reference.
Delete all email messages - Microsoft Support
Delete email in Outlook.com - Microsoft Support
I hope the steps I provided can help you.
Feel free to post back if you need further assistance.
Sincerely,
Hardyjoe.J|Microsoft Community Support Specialist