Why are Add-ons not supported for versions of Postbox purchased through the Mac App Store?

Apple requires that applications be self-contained, single application installation bundles that do not install code or resources in other locations. As such, we cannot support add-ons for versions of Postbox sold and updated through the Mac App Store. We're currently working with Apple to determine if there are any possible work-arounds to these restrictions. If we do find a work-around, or if Apple revises their guidelines, we'll be sure to submit a new version with this functionality to the Mac App Store.

If I purchase through the Mac App Store, can I download a version from Postbox that supports Add-ons?

Yes, and you can do so free of charge! Just download the latest version of Postbox from our website, and replace the copy you have in the Applications folder.

Note: Once you copy the version of Postbox from our website into the Applications folder, updates from this point forward will be managed by Postbox's update system as opposed to the Mac App Store.