I just tried another dummy account with AOL Mail (a dinosaur) and it came through fine. I don't understand this.
I used mailfence.. It's extreme barebones but it works and is easy to setup. (not needing a damn phone like google and yahoo now) They even let you use another email for recovery. Yeah, it doesn't make much sense. As I said in one of my earlier posts.. Email "compatibility issues" and blocking seem to be happening more and more. Even medium size sites that do business are sometimes affected. Especially if they deal with things big business doesn't like. (see Nutaku being blocked by Yahoo mail)
Like I said, just let me know if you want me to check. (to make things easier on you)