Certificate problems in Outlook often show up as warnings about untrusted connections, and they can make your inbox stop working. This article suggests practical fixes like checking certificate trust chains and updating your Outlook settings. When certificate issues have left your PST file unstable or partially unreadable, the MSOutlookHelp PST Repair Tool helps fix the Outlook Certificate Error by restoring the corrupted file safely. It keeps email properties like subject, time, and recipients exactly as they were and supports batch repair if you have more than one PST file. The software also keeps important attachments intact, making sure nothing valuable is lost in the process.