@miklb I think you can do that with Postbox, though it might require some configuring: postbox-inc.com

Are there any of those desktop email clients with the master inbox with a focus mode to hide all but one?

In reply to

@syneryder That does look intriguing. I’m going to give it a test run today. Thanks.!

@miklb mail app you can view integrated or box by box ... Is that what you mean?