POP Peeper FAQ
How do I fix "Error (offline)"
Your system is currently set to work "offline." You can change this by opening either Internet Explorer or Outlook Express, opening the "File" menu and uncheck "Work Offline." POP Peeper can automatically switch you to "Work Online" -- from the main menu, select Tools / Run PPtweaker; select the 'Connections' page; enable "Force work online."
Note: As of POP Peeper v4.0, "Force work online" is enabled by default.