Note Number 5 above, You must have Classroom as the subject of the email and to further expediate this you could add your Username here after Classroom as in:
Hi Im So Glad ... I Just joined after years of learning from your forums
Is there any way i could have the e mail adress to join the classroom please , the link , for some reason isn't working for me. Because I would really apreciate being able to join. Thank you.