Postbox Add-ons / Extensions Support
Postbox provides a mechanism that allows add-ons or extensions from Postbox or 3rd party developers to be installed within Postbox.
However, it is up to each add-on developer to support the functionality of the add-ons they author. Postbox does not provide support for add-ons developed by third parties. If an add-on isn't working as you expect, or if an add-on is causing problems within Postbox, we recommend contacting the add-on developer directly.
Unmodified Mozilla add-ons do not work within Postbox at this time. Developers of existing Mozilla add-ons need to port their add-ons to Postbox. Sometimes this can be as simple as changing a few parameters, such as product, version, etc., other times the porting effort may be more complex.