Mail - Smart Mailboxes

How to set up a Smart Mailbox

For example, if you want all e-mails from employees at IMV (Department of Musicology) to appear in a Smart Mailbox:

Select Mailbox → New Smart Mailbox (or click the Plus button in the lower left corner and select Smart Mailbox from the menu). 

Give your mailbox an appropriate name, eg. Musicology and define it's state to  From: Contains: imv:

To include a message from the trash in Mail, enable option Include messages from Trash. You can do the same if you want to include outgoing e-mail,, Include message from Sent. 

Finish by clicking OK, and a new smart mailbox now appears in the left column under the header Smart Mailboxes.

This type of meilbox will read out all the e-mail messages that meets the criteria from the other mailboxes, but no e-mails are moved. It also displays the number of unread e-mails that satisfy the criterion.

You may safely delete a Smart Mailbox. Then you remove the rule / view and not any of the e-mail messages that satisfied the criterion.