sending email to unknown recipient @tpo gets transient error instead of permanent?
One common error that people make in addressing email is sending to
email@example.com instead of
firstname.lastname@example.org. This ends up bouncing after a delay of a few days (with a 4xx transient error, which the sending MTA retries). It should probably either bounce immediately with a 5xx permanent error, or maybe automatically forward to
email@example.com. The delayed bounce will prevent timely receipt of the email (when later correctly addressed), and might cause email to be lost completely (when the sender forgets to resend it).
I'm not sure whether this is a more general MTA config issue, or if it only affects lists.
Excerpt from bounce:
** Delivery incomplete ** There was a temporary problem delivering your message to firstname.lastname@example.org. Gmail will retry for 46 more hours. You'll be notified if the delivery fails permanently. The response from the remote server was: 450 4.1.1 <email@example.com>: Recipient address rejected: unverified address: User unknown in virtual alias table
Complete raw bounce message, with headers at https://share.riseup.net/#KUuavJIwtD9SWiEADyeJCQ Original message at https://share.riseup.net/#V55WMe5UozEk85fgKUM6Aw Original was sent via gmail's SMTP server, with headers
To: firstname.lastname@example.org From: Taylor Yu <email@example.com>
Date: Thu, 13 Jun 2019 22:36:02 -0500