For a fresh Carbonio install, I’d double-check the hostname/FQDN, DNS records, and /etc/hosts before troubleshooting anything deeper. Also make sure t...

For calendar sync issues, I’d first check that the account is using the correct CalDAV settings and that sync is enabled on both sides. If events are ...

Before retrying the upgrade, I’d check the upgrade logs for the first actual error rather than the final failure message. Also make sure there’s enoug...

Have you checked the mailbox-level forwarding settings and the server logs? If forwarding works for some messages but not others, I’d also check the f...

I’d first check the Carbonio logs around the time the access issue happens. Also worth confirming the affected service is running and that there isn’t...

A "connection refused" error usually means the target service isn't actually listening yet, not just a firewall issue. I'd check that the related Carb...