Hi Dave,
Yes, forum administrators (and most likely the moderators too) will have access to user account history including the IP addresses used when posting and logging in. If you register a new account at the same forum with a different email address they will most likely be able to figure out that it's you if they are paying attention or have some automation in place to detect "alter egos" in their forums. Even if you change your email and IP addresses your web browser cookies could give you away too.
To get most of the way around all of this you would need to use the new email address, a new computer or web browser (if you usually use Firefox, use Chrome for that forum), and try an anonymous proxy service so you're not coming from the same IP address (careful, many of them are scams).
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