You can use the command console to find your IP address. But if you are unsure of which IP address to look up, please check the bounced mail message and headers for a line that looks similar to this:
Please see https://www.ers.trendmicro.com/reputations/index?ip_address=127.0.0.2
The IP address you would want to check, in this case, is 127.0.0.2.