mailman3--- via Mailman-users writes:

If i try to login via nexcloud, postorius redirect me to the nextcloud, where i successful login, and redirected to postorius But i'm not logged in postorius.

I don't know of a howto for Mailman and socialauth.

The socialauth I've configured has been for corporate environments, so there was a ground source of truth for IDs that happened to also provide the ground source of truth for email addresses. So everything just worked and there was no debugging to do. :-(

First, you need to understand that there's no automatic connection between your socialauth identity and your Mailman identity, and that your email address is not your Mailman identity, although it is linked to your Mailman identity.[1]

Now, the traditional identity in email is an email address, and the authentication procedure is to make the user prove they can read the mailbox. That is still necessary, so email addresses are still very closely bound to the identity (Mailman User object). Then there are these questions:

1. Does Nextcloud provide an email address as identifying information?
2. Is it the right address (ie, one of the ones linked to your Postorius login)?
3. Is that address verified in Postorius?

If none of those questions help you figure out the problem, you'll need to explain exactly what data Nextcloud is providing to Django socialauth, and how Django socialauth is supposed to connect that to a Postorius/Mailman User object.

Steve

Footnotes: [1] The identities in Mailman are quite complex. From Mailman's point of view, the identity is in a User object in Mailman core's database. That User is *not* exposed to world, instead, a separate application (Postorius in your case, and for most sites) provides a proxy object that automatically synchronizes with the core User object. Besides the proxy object, Postorius also provides authentication services. Those services are delegated to Django, which handles both traditional password authentication as well as "socialauth". Then the socialauth plugin receives some kind of identifier (not an identity!) from the identity provider.