Impossible d'envoyer ou de recevoir des e-mail

Hi,

Sorry to jump in and speak in English. I am trying to troubleshoot my mail and I am a bit desperate. I read here that you seem to have fixed a similar problem to mine (if I understood correctly with the help of the translator)

On my upgraded Yunohost server I could find the value
virtual_mailbox_domains = /etc/postfix/virtual-mailbox-domains

while on another healthy yunohost server I have (previous yunohost version) it shows:
virtual_mailbox_domains = ldap:/etc/postfix/ldap-domains.cf

I also found the faulty one was missing a file the healthy one did have:
/etc/postfix/ldap-domains.cf

Would you please come to Mail loops back to myself - probably related to 12.1 upgrade and guide me on how to exactly fix it?

Thank you very much in advance.