No, I don't think you are getting such good advice
And I don't think you should wait for another mail from them. The next step might be a UDRP, that you could lose by default if you don't present an adequate defense. You should address their claims, and decide if they have merit or not.
Just because you did not find an exact match for the TM, doesn't mean they don't have TM rights. Their TM does not even have to be registered.
It depends on the circumstances and many things, like how you have been using the domain. For example, if it's been parked and showing ads for their competitors, you could be violating their TM without knowing it. But your are still ultimately responsible as the domain holder.
So what are their assertions ?
You're right, there is some
really terrible advice in this thread.
----For Op-----
There are, however, some decent questions that have been asked that you need to consider. As usual, advice in general is difficult to give without knowing the actual details
How long have you owned the domain?
How strong is the mark? (The fact that you've not heard of them actually refutes bad faith.) How much reach does it have?
What is their first use in commerce?
How generic/applicable is the domain name to be put to other uses not infringing?
What have you done with the domain? (Does it infringe directly? i.e. through ads)
Most importantly, do you actually have a legitimate interest in the name?
If you respond you should respond with minimal details and no bullshit.
Don't talk about your research into their TM, don't make an offer for sale, and don't do the "It's cheaper at $1200 than filing a UDRP" thing. I suggest that domainers are unethical and get slapped down by everyone taking offence and then people suggest basically manipulating the system a little. Don't talk about Reverse Hijacking (they may legitimately feel that they have a real interest) and just is aggravating people that are already not thrilled with things.
Finally, factor in the reality that a strong Trademark can drastically reduce and diminish the value of your name as that's baggage that any future buyer has to overcome or be wary of. You should disclose this warning on future sales.
After answering all the questions above you may feel there are no UDRP issues.
"I registered the domain in 2005 for my own use. Thankyou for your communication".
It lets them know you are alive. It lets them know you will respond and gives them no leverage.
If you have no legitimate interest in the name don't bother making one up. Panels have seen through that before. If you claim legitimate interest you would have supporting evidence and your one page lander and a couple of forum posts mean nothing.