Mailing Lists are the primary communication channels for all projects at The Apache Software Foundation. Therefore, this applies to Apache PDFBox, too. If you have any questions about or problems with Apache PDFBox, you can get them addressed on the Users Mailing List. If you like to participate in the development of Apache PDFBox, the Developer Mailing List is the place to be. If you like to keep track of what's being changed inside the project, you can subscribe to the Commit Mailing list.
This is where you can post your questions about and problems with PDFBox. All committers (developers) are required to be subscribed to this mailing list. When in doubt which mailing list to use, use this one.
This is where the committers and interested contributors discuss the further development of Apache PDFBox.
This is where all the notification mails from Subversion commits and issue tracker changes get sent. This mailing list is not used for discussions.