如果 Exchange Server OAuth 憑證已過期，則無法登入 Outlook 網頁版或 EAC

 無法使用過期的 OAuth 憑證存取 OWA/EAC - Exchange | Microsoft Learn

 (Get-AuthConfig).CurrentCertificateThumbprint | Get-ExchangeCertificate | Format-List

 

 New-ExchangeCertificate -KeySize 2048 -PrivateKeyExportable $true -SubjectName "cn=Microsoft Exchange Server Auth Certificate" -FriendlyName "Microsoft Exchange Server Auth Certificate" -DomainName @()

Set-AuthConfig -NewCertificateThumbprint <ThumbprintFromStep1> -NewCertificateEffectiveDate (Get-Date)
Set-AuthConfig -PublishCertificate
Set-AuthConfig -ClearPreviousCertificate

Restart-WebAppPool MSExchangeOWAAppPool
Restart-WebAppPool MSExchangeECPAppPool