Fix Outlook Security Certificate Error

[Abhilash Dogra]

Having trouble with Outlook showing security certificate error? This article explains why Outlook displays errors such as “certificate expired,” “mismatched domain,” or “untrusted authority,” and how these prevent a secure email connection. It provides simple manual fixes, such as correcting your system's date/time, checking or installing a trusted root certificate, and clearing the SSL cache. For deeper issues—especially when certificate errors have damaged your PST file, the MSOutlookHelp Outlook PST Repair Tool is offered as a professional remedy. It lets you scan and restore corrupted PST files, helping recover emails that couldn’t connect due to certificate issues. Furthermore, this tool provides multiple recovery modes to handle different degrees of corruption efficiently.