First register email not sent

Support
4

Because the registration email never arrived I’ve activated the admin account using the command line.

I logged in with the admin account and sent a test email to anotheruser@anotherdomain.org from Admin / Email settings / server settings → send test email.

This test email was sent immediately as we can see below and was delivered in my inbox :

root@my-vps:/var/discourse# ./launcher enter app
x86_64 arch detected.
root@my-vps-app:/var/www/discourse# rails console
Loading production environment (Rails 8.0.5)
discourse(prod)> EmailLog.all.pluck(:to_address, :email_type, :created_at, :smtp_transaction_response)
=> 
[["user@domain.org",
  "test_message",
  2026-05-13 16:23:41.417177000 UTC +00:00,
  "250 2.0.0 Ok: queued as 4B4DDB0059A"],
 ["anotheruser@anotherdomain.org",
  "test_message",
  2026-05-16 14:44:42.978862000 UTC +00:00,
  "250 2.0.0 Ok: queued as D79DFB00573"]]

Then I tried to register with the same email address (anotheruser@anotherdomain.org) but the registration email wasn’t delivered (and not sent because it doesn’t appear in the logs from the rail console).

In conclusion test emails are sent and delivered but registration emails are not sent even with we find a trace in production.log :

cat production.log | grep anotheruser
  Parameters: {"email_address" => "anotheruser@anotherdomain.org"}
Started GET "/u/check_email?email=anotheruser%40anotherdomain.org" for xxx.xxx.xxx.xxx at 2026-05-16 17:40:45 +0000
  Parameters: {"email" => "anotheruser@anotherdomain.org"}
  Parameters: {"email" => "anotheruser@anotherdomain.org", "password" => "[FILTERED]", "username" => "NewUser", "password_confirmation" => "[FILTERED]", "challenge" => "xxxxxxxx", "timezone" => "Europe/Paris"}

People can’t register so what can I do to fix this ?