Anyone migrating from b2evolution or any other blogging software which does not fully support importing into WordPress will feel a world of pain to get the original blog’s content right. If you don’t pay attention, you will receive many 404’s as the generic importers (or even the old b2evolution importer) will import with wrong permalinks (i.e. in my case 80% of my posts had the wrong date-slug).
While Google Webmaster toolkit came to the rescue in restoring the correct slugs and forced me to manually updating posts and Permalinks, in hindsight this was completely unnecessary, as 404 Redirected would have done most of the work for me.
The plugin provides “Automatic Redirects” which will match the inbound Permalink to the existing articles through a 301 redirect and fixes almost all issues.
The biggest problem I encountered after the import was that the tag-format changes in WordPress (b2evolution uses “/ps3:” whereas WordPress uses “/tag/ps3”) which results in many errors.
The 404 Redirected plugin captures all 404’s and you can view them via the “Captured 404 URLs” tab. The awesome feature is, that any 404 URL can then be manually mapped to a post, a tag or a category:
Within a few days I managed to resolve most of the 404 errors and every once in a while some additional 404’s for tags and categories require re-mapping which is a really painless exercise nowadays.