Do search engines penalize for too many domain aliases?

[caliboyz]

I have a main domain name and 20+ related alias domains pointing to it. Is there a danger, penalty or concern that I should be aware of related to alias domains? I saw something on Google "Apps Administration" under "What is a domain alias" saying  "you can add up to 20 domian aliases" but I don't use Google Apps.  Please advise...

Thank you,

Chris

[Syed1]

I don't think there will be a "penalty" as per say but those links could definitely be discounted or filtered out if they are hosted on the same server (IP range).

We have many such domains pointing to our main domain and there is no issue at all. Do make sure that those 20 domains are clean and are not in 'bad neighbourhood' (bad links, hosted with bad sites, etc) as penalty could pass through a 301 redirect.

[Dr-Pete]

I agree with Syed - it really depends on what you're doing with them. If they're just placeholders that have never had a site on them, Google probably won't notice at all. If these were previously interconnected micro-sites and then you turned around and funneled them into one site to capture all the link-juice, then it could certainly look a little manipulative. What's the purpose of the 20+ domains?