454 4.7.1 <firstname.lastname@example.org>: Relay access denied
This is a commonly seen email failure error by web hosts, website owners and server owners who run Postfix mail server. 454 error usually happens while sending to and receiving from external domains.
In our role as Hosting Support Engineers for web hosting companies, we handle many such mail errors and fix them. Here, we’ll see what causes “454 4.7.1 Relay access denied” error and how we fix it. (more…)