chat-api.comは安全ですか？

Instead of giving support by answering your emails, they are blocking your account. Fixing errors on their service seems to be too costly. One of their main error is that you are not able for bringing the sent messages together with the confirmations coming from their service. All what you get is the address and maybe the scrambled content of the sent message. Error information are not getting delivered JSON formatted, this information comes as system/Java error on a normal website. So even their error handling is not working like from a professional. As found at their instructions, you should be able to include UTF-16 symbols into the messages. If you do so, then you only get a script error like described before. It looks that the service got designed from script kiddies without any commercial IT experience.