Best Practice when Redirecting Whole Domains

• I'm moving all my clients from old servers to new servers and am concerned about redirecting multiple domains to one site. I recently heard that Google is penalizing sites with multiple domains redirecting to one site. I want to make sure I get everything set up properly all at once since now is the ideal time to clean up an old SEO strategy.

  What we had done in the past is the following:
  domain.com (our main live website)
  domain1.com (related domain with keywords in name)
  domain2.com (related domain with keywords in name)
  domain3.com (related domain with keywords in name)

  We would create a blank index page with an immediate html redirect on domain1.com to redirect to domain.com. We would then point domain2 and domain3, etc. to domain1. To tell you the truth, I'm unsure why we did it this way, but this was quite a few years ago and it seemed to work very well at that time.

  So the question is; will pointing all three domain names into one site trigger duplicate content or any other penalty? What's the best way to do this?

Answer:

We haven't any reason to believe that Google is penalizing sites with multiple domains redirecting to one site. We ourselves have lots of clients with "extra" domains that we 301 redirect to their main sites. Common uses for such domains include tracking for print, tv, & radio ads.

You might be confused about the terminology. To be clear, a redirect would be a 301 server redirect from domainA.com to maindomain.com. This has always been acceptable to Google and we have every reason to believe it will remain so.

Pointing, however, typically means domainA.com, domainb.com etc. all show the SAME content as maindomain.com. And that IS a problem because Google will see it as massive duplicate content. Technically, this means you have the extra domains DNS setting "pointed" at the same web server location as your main domain.

There are people that have different definitions of the word "Pointing" when it comes to this so this term can create some confusion. In the above example we are not talking about domainA.com display...