How to See What Mac OS X Mail is Doing in the Background

by Heinz Tschabitscher
Updated October 19, 2016

Mac OS X Mail loves to do things in the background. It then displays these spinning arrows indicating activity, but it does not tell you up front what it is doing right now (downloading a huge message, updating the IMAP cache, sending an attachment,…).

Fortunately, you can still find out about Mac OS X Mail's hidden activities.

See What Mac OS X Mail is Doing in the Background

To watch background activities in Mac OS X Mail:

  • Select Window | Activity (or Window | Show Activity Viewer) from the menu in Mac OS X Mail.

If you want to get rid of the Activity Viewer window again, either close it or select Window | Hide Activity Viewer from the menu.

And if you refer to it often, you can also toggle the Mac OS X Mail Activity Viewer by pressing Command-Option-0 or Command-0, depending on the Mac OS X Mail version.