Please note that Posterous is shutting down its service on April 30. Please check out this post for details. When the service shuts down, this importer will no longer function, as it relies on the service being up in order to fetch content.
If you wish to keep a copy of your Posterous content, it's very important that you follow the backup procedure before the shutdown date. The steps are as follows:
- Go to http://posterous.com/#backup.
- Click to request a backup of your Space by clicking “Request Backup” next to your Space name.
- When your backup is ready, you'll receive an email.
- Return to http://posterous.com/#backup to download a .zip file.
This file will contain all of your posts and media along with a file named wordpress_import_1.xml. While you can import your posts using that file, media will not be automatically imported, and there are at present some issues (pending resolution on Posterous's end) with the export file. You should download it in any case so that you have all of your raw data.
The Posterous importer on WordPress.com handles some of the issues with the file and is able to process most of the media, resulting in a mostly clean import. If you import into WordPress.com, you can then export and then import into your self-hosted blog. It's not an optimal solution, but it certainly beats losing all of your data.