User complaining of empty Sent Items folder?

[Joey Link]

I have one user who says after he sends a message his Sent Items folder is empty. Is this an option he may have selected, a bug, or what?

[DeanLag]

Must be enabled in User CP > Edit Options > Check: Save a copy of sent messages in my Sent Items folder by default.

Alternatively, you can check it before sending a new PM, located below the PM itself:
Save a copy of this message in your Sent Items folder.