[MlMt] How do I only show unread messages in smart mailboxes

[Jason Davies]

On 6 Jan 2014, at 17:46, Jon Nall wrote:

> I want to create a smart mailbox that (among other criteria) only 
> contains unread messages. I perused all of the criteria but with the 
> exception of possibly #Is-New-Message (which I couldn't find any docs 
> on), I came up empty.
>
> Any advice on how to create a smart mailbox that contains only unread 
> mail?

set conditions to tag is 'not seen' for all (relevant) mailboxes.