[squid-users] This list generates a forward loop ...

[Walter H.]

Hello,

On every post I get an error mail back:

<BEGIN>
Subject:   	Undelivered Mail Returned to Sender
From:   	"Mail Delivery System" <MAILER-DAEMON at squid-cache.org>
Date:   	Tue, July 18, 2017 15:36
To:   	        ...
Priority:   	Normal

This is the mail system at host lists.squid-cache.org.

I'm sorry to have to inform you that your message could not
be delivered to one or more recipients. It's attached below.

For further assistance, please send mail to postmaster.

If you do so, please include this problem report. You can
delete your own text from the attached returned message.

                   The mail system

<squid-users at squid-cache.org> (expanded from
    <squid-users at lists.squid-cache.org>): mail forwarding loop for
    squid-users at squid-cache.org
<END>

Why?

Thanks,
Walter