Emails sent to list don't get forwarded to list members

[eauchat]

Describe the bug

When a member sends a mail to the list, nothing happens, and other members don't receive anything.

Context

• Hardware: computer
• YunoHost version: 11.0.10.2
• I have access to my server: Through SSH, through the webadmin
• Are you in a special context or did you perform some particular tweaking on your YunoHost instance?: yes
  • If yes, please explain: yunohost is running in a VM
• Using, or trying to install package version/branch: 1.0~ynh2

Steps to reproduce

• Install mailman3 (yunohost app install mailman3 -a "domain=lists.domain.tld&admin=someuser&is_public=yes")
• Create a mailing list
• Subscribe a few users from the web interface
• Send a mail to somelist@lists.domain.tld from one of the member's email adress

Expected behavior

Message sent to the list will be forwarded to each member of the list. Or at least the member will get a response email mentioning why it will not be forwarded. Or the message should appear in "Held message" in the web interface.

None of the previous is happening. So I guess there is an issue somewhere, but don't know the appropriate way to debug it.

Side note

I'll probably open a specific separate bug report, but if I subscribe a user, the user gets to receive the welcoming email properly, but if I try to add a "list:user:notice:welcome" template, when subscribing a new user, I get the following error (subscription still seem to work, but the user doesn't receive any welcoming email):

HTTP Error 400: HTTPSConnectionPool(host='lists.domain.tld', port=443): Max retries exceeded with url: /postorius/api/templates/list/listname.lists.domain.tld/list:user:notice:welcome (Caused by SSLError(SSLCertVerificationError(1, '[SSL: CERTIFICATE_VERIFY_FAILED] certificate verify failed: self signed certificate in certificate chain (_ssl.c:1123)'))) 

[eauchat]

Well it seems the issue was coming from this: PermissionError: [Errno 13] Permission denied: '/var/lib/mailman3/lists/lisname.lists.domain.tld/digest.mmdf'

The digest.mmdf file doesn't exist, hence why this error is occurring.

Deactivating digest mode resolved the issue for me. But I guess there is still something that's not how it should be, with this missing file.