Can I return to Thailand after being denied entry two years ago on a volunteer visa?

You know.if your black listed! How long did you over stay? What was the fine?

I think those in this forum are not with Thai immigration though there may be some spies. So the "you" may be misplaced.

And those who contribute to this are mostly using their own experience or knowledge and should never be used as law.

Now back to your question. The statement you were refused entry means that something happened and you couldn't enter Thailand. This probably means that probably have a ban for a certain period and a probation period of another few years where your entry and exit will be closely watched. Regardless of your passport, your biometrics including face photo is already in the system and can be called up.

So in terms of a blacklist, it all depends on the reason for your denial of entry. There have been some who got denied entry and even after 3 or 4 years and a new passport, when they fly in, they get asked a lot of questions and were required to show an exit ticket. (this is my personal experience). But whatever it is, the laws are clear to all, if it has been abused and thus denial of entry is issued, then the person will need to be more careful and check with the laws that have been stated in the immigration website. Laws and rules do keep changing, so just check it out.

How are we going to know if you been blacklisted? Only way to find out is to either try and enter or possibly a Visa Agent can help you.

New passport doesn't "reset" anything like that. There are only 2 people who can answer this question.

1) Immigration at the airport/border

2) By yourself if you did try it out.