I need a zimbra EXPERT.

I have a zimbra server with multiple domains. Sending from the server works fine, however emails received by the server get stuck in the queue and do not get delivered to mailboxes. I need someone who is experienced with Zimbra to resolve this issue.
I DO NOT wish to lose the emails currently in the queue.
You will need to use anydesk or teamviewer to access the site sorry. No direct SSH.

Thannks