[mlmmj] mlmmj error: "Have to invoke either as root or as the user owning listdir"

Greetings,

I just installed mlmmj on SuSE Linux Enterprise Server 15 SP4 running a 
mail server thanks to postfix and dovecot.

I can create a mailing list and subscribe my e-mail with mlmmj-sub 
without any problem.

When I get the e-mail from mlmmj, I send the answer accepting the 
subscription but get a new e-mail in return from mlmmj sying:

_Subject: Undelivered Mail Returned to Sender _

This is the mail system at host <MY_SERVER>.

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

<mlmmj_list_1_dav+confsub-55f8b4567a40e8c8-eric.davanture=orange.fr@MY_DOMAIN.com>:
     Command died with status 1: "/usr/bin/mlmmj-receive -L
     /var/vmail/mlmmj/mlmmj_list_1_DAV/". Command output: Have to invoke either
     as root or as the user owning listdir

I am blocked here and can't reach finding what the problem could be.
Any help will be greatly appreciated.
Thanks a lot by now.

-- 
Librement vôtre / Libremente suyo / Freely yours,
*Eric J.P.E. Davanture - [email protected]
*
_Approximate location:_ Planet Earth < Solar System < Milky Way Galaxy < 
Local Group < Virgo Cluster < Laniakea Supercluster < known Universe 
(https://youtu.be/P6cw5Yv-zqU)
*There is NO CLOUD, just other people's computers !*

Greetings,

I just installed mlmmj on SuSE Linux Enterprise Server 15 SP4
running a mail server thanks to postfix and dovecot.

I can create a mailing list and subscribe my e-mail with
mlmmj-sub without any problem.

When I get the e-mail from mlmmj, I send the answer accepting the
subscription but get a new e-mail in return from mlmmj sying:

Subject: Undelivered Mail Returned to Sender

This is the mail system at host <MY_SERVER>.

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

<mlmmj_list_1_dav+confsub-55f8b4567a40e8c8-eric.davanture=orange.fr@MY_DOMAIN.com> :
Command died with status 1: "/usr/bin/mlmmj-receive -L
/var/vmail/mlmmj/mlmmj_list_1_DAV/". Command output: Have to invoke either
as root or as the user owning listdir

I am blocked here and can't reach finding
what the problem could be.

Any help will be greatly appreciated.

Thanks a lot by now.

--

Librement vôtre / Libremente suyo / Freely yours,

Eric J.P.E. Davanture - [email protected]

Approximate location: Planet Earth < Solar System <
Milky Way Galaxy < Local Group < Virgo Cluster < Laniakea
Supercluster < known Universe ( https://youtu.be/P6cw5Yv-zqU )

There is NO CLOUD, just other people's computers !