Generally speaking, if you want to know how the school you want to apply for received the recommendation letter, you will know it when you apply for filling out the form. When filling in the form, you can only fill in the specific information of the referee. If you can send a letter of recommendation by yourself, you will have the option to upload a letter of recommendation when you finally submit the document, and then the school will automatically send an email to the teacher to confirm the identity of their referee. I remember that many universities in Britain said that they needed an email address ending with the school domain name, which was more authoritative and reliable. Another is that after you fill in the referee information, the school will prompt you to confirm whether the information is correct, and then they will send a link to the referee's email, and then let the teacher upload it by himself according to the provided link.