How to Open Two Mailboxes at the Same Time in Mac OS X Mail

When you launch Mac OS X Mail, it opens one mailbox viewer by default. Here, you can open different mailboxes, but never two at the same time. Never?

Open Two Mailboxes at the Same Time in Mac OS X Mail

To view two or more folders at the same time in Mac OS X Mail:

• Select File | New Viewer Window from the Mac OS X Mail menu.
  • You can also press Command-Option-N.

A new mailbox viewer pops up, ready to show you mailbox contents and messages in the preview pane.

(Updated December 2011)