@jotamachuca @gulzarahmad
First, you check the site_url ="your_server/project_name/public".
second, Open your Mailboxservice file in your project from the given below path.
your_project\vendor\uvdesk\mailbox-component\Services\MailboxService.php
Now, Open the updated Mailboxservice file from here.
Copy the updated Mailboxservice file & paste in your project mailboxService file.
Now, run
php bin/console uvdesk:refresh-mailbox test@test.com
Hope this will resolved your issue, If you still get the same error or any issue Please let me know