Issue: The MSG appliance has stopped sending emails out to external domain addressesSending emails to internal domain addresses works without issueReceiving emails from any sender works normallyOutgoing connector is showing errors about invalid certificatesResolution: The problem might be caused by an invalid or expired certificate on the MSG-applianceTo verify the active certificate: Log in to the MSG web UISelect the System-tab on the top of the pageNavigate to System->Certificates->Services using the menu on the left-hand sideNote which certificate is in use for the different servicesNavigate to System->Certificates->CertificatesVerify the validity of the certificate(s) that is in use If the wrong certificate is in use, it can be changed on the Services-page from step 3. Use the dropdown menus to change the certificate for all services and click Save changes.If the certificate in use has expired, use the Generate Certificate Request-button on the Certificates-page from step 5 to start the process of adding a new certificate to the MSG-appliance. Use the created certificate request with an acquired certificate from a certificate vendor to make a new certificate for the MSG, then import the new certificate into the appliance using the Import-button, also on the Certificates-page from step 5. After this, use the instructions mentioned above to change the active certificate for all services, and save the changes.