Am 27.07.2016 um 02:34 schrieb Mike Kadin: > Result: 25: SMTP error from remote mail server after RCPT TO:<
> test123@???>: 454 4.7.1 <test123@???>: Relay
> access denied
> ```
>
> Do you think Uber's DNS configuration for help.uber.com is problematic? Is
> No, thats thats a bad configuration of the mailserver. It believes, it
it not responsible for "frontends.uber.com".
So it denies your messages, as you try to use it as an open relay, which
it isn't.
Put the domain in the localdomains list and it will stop.