Dear,

I'm glad to hear that you've successfully updated the core to RC2. Regarding the issue with updating "Mailbox," it seems there might be a specific configuration or compatibility issue that needs attention. Have you checked if the latest updates or patches from mainaja's support or documentation address this? Sometimes, certain modules or plugins require specific steps or dependencies to update seamlessly.

If you haven't already, I would recommend reaching out to Mainaja's support team for assistance. They may have insights or a solution tailored to the "Mailbox" update process that could resolve the issue more efficiently. Providing them with details about your current setup and any error messages you're encountering will help expedite the troubleshooting process.

Feel free to keep me updated on your progress, and I'm here to assist further if you need more guidance or have any other questions related to Mainaja or your updates.

Best regards,  

Aqsa