Update certificate on Send and Receive connectors in Exchange Hybrid - aaqibwani/M365 GitHub Wiki

  1. Identify the certificate and copy its thumbprint:
Get-ExchangeCertificate
  1. Run:
$cert = Get-ExchangeCertificate -Thumbprint <paste the thumbprint here>

$tlscertificatename = "<I>" + $($cert.Issuer) + "<S>" + $($cert.Subject)

Set-SendConnector "Outbound to Office 365" -TlsCertificateName $tlscertificatename

Set-ReceiveConnector "Default Frontend" -TlsCertificateName $tlscertificatename
  1. Restart the Transport service