Forum Moderators: phranque
The way we saw it, there were a few types of re-redirect available, for example:
1) through IIS either by pointing to same directory, or by having one IIS account accept 2 domain names.
2) a simple coded redirect either using Meta-refresh or some ASP redirects.
We did a lot of reading to see the effects of this, and found that google, and some others SE's do not like redirects, or mirror sites.
We changed a lot of our sites to have one, and only one, domain name. Nothing automatically re-directed to this domain. We then created a separate domain, where we pointed all spare domains. This directory would have a page saying "The site you are looking for has move, please click here to view it". which was linked through to the main site.
To try and explain a little better. We narrowed it down to www.maindomain.com. Nothing auto redirected to this domain. We then created www.seconddomain.com. We then redirected all other relevant site domains to www.seconddomain.com. (other domains includeded URL's such as www.anotherdomain.com, anotherdomain2.com etc).
We then put up a short "this page has moved" file in the www.seconddomain.com directory, and added a manual click through to www.maindomain.com
This seems to have worked in our favour, as our site has since jumped around 20 places in google.
hope this helps