24 hours ago or so, I tried to post to the PRO-CL list from my gmail account and here is below what googlemail answered me back!

Is there a problem with the mailing-list server on common-lisp.net?

---------- Forwarded message ---------
From: Mail Delivery Subsystem <mailer-daemon@googlemail.com>
Date: Tue, Dec 8, 2020 at 12:11 AM
Subject: Delivery Status Notification (Delay)
To: <jean.claude.beaudoin@gmail.com>

Delivery incomplete

There was a temporary problem delivering your message to pro@common-lisp.net. Gmail will retry for 47 more hours. You'll be notified if the delivery fails permanently.

The response from the remote server was:

451 Temporary local problem - please try later

---------- Forwarded message ----------
From: Jean-Claude Beaudoin <jean.claude.beaudoin@gmail.com>
To: Common Lisp pros <pro@common-lisp.net>
Cc:
Bcc:
Date: Sun, 6 Dec 2020 23:52:57 -0500
Subject: In CLOS, instance remorphing considered useless in practice?
----- Message truncated -----