shared mailbox in Snappy Mail, the mailbox unintentionally becomes accessible to other user accounts

[RGES-17]

Summary
When configuring a shared mailbox in Snappy Mail, the mailbox unintentionally becomes accessible to other user accounts.

Initial Hypothesis
It appeared that some general settings in Snappy Mail’s admin panel or Nextcloud’s configuration might be causing shared sessions or unexpected behavior. Various settings (language preferences, multiple identities, additional accounts) were adjusted, but the problem persisted.

Key Observation
Initially, mailbox configuration was done using the Nextcloud Impersonate plugin, allowing an administrator to temporarily switch to another user’s account. This process caused the mailbox to be visible in other accounts.

Test Without Impersonate
When the mailbox was configured directly from the end user’s account, without using Impersonate, the issue did not occur:

• Each user only sees mailboxes explicitly assigned to them.
• No unexpected sharing or session crossover happens.

Conclusion and Final Hypothesis
Using Impersonate seems to result in mailbox settings being saved in a way that affects other accounts. This could be due to a shared configuration session or incorrectly assigned user data.

I am a French-speaking user, and I am not used to using gihub. I share with you the analysis of an "abnormal" behavior of snappy mail, with the Impersonate plugin, which I used to open access to mailboxes on nextcloud accounts.

I don't know if there is a solution to this bug yet.

That said, thank you for the tools and the work accomplished.