Does it matter if you get it by mail or email? Just check both, it doesn’t follow that if they send it to you in either form, they will do it every time, there are those who received an email for AOR, then mail for test invite then email again for oath invite. In short they are not consistent at times. Just make sure you check your ecas at least 3x a week, I never received my AOR from them only found out they sent it thru ecas, but both test and oath invites were sent thru emails