301 redirects not working I'm moving a site from EE to Craft. All is well but the redirects from the old URLs to the new do not work.

I have tried:


SproutSEO Redirects
(https://sprout.barrelstrengthdesign.com/craft-plugins/seo/docs/getting-started/redirects) - Results in a Craft 404
Retour (https://github.com/nystudio107/retour) - Results in a Craft
404
Reroute (https://github.com/davist11/craft-reroute) - Results in a
Craft 404
.htaccess redirect - Results in Craft 404


The only thing I can think of is that Craft is somehow getting ahead of these solutions and running with the 404.

Any assistance would be appreciated.
I wrote the Retour plugin; it will definitely work. However it only kicks in after 404 error is thrown by Craft. So if some route resolves to the URL in question, it won't kick in (because, by definition, it is then not a 404)