You said > Uber users can initiate support tickets by replying to certain emails; the > replies go to some_unique_address@???.
But then > Result: 25: SMTP error from remote mail server after RCPT TO:<
> test123@???>: 454 4.7.1 <test123@???>: Relay > access denied
I would rather think, the sender made a simple mistake.
frontends.uber.com is not help.uber.com
Does test123@??? exist at all? You said they need to use
"some_unique_address@???"
