HMRC secure mailbox - Partial Outage

We have identified that customers in the UK are receiving an "It has not been possible to establish a connection to your HMRC Mailbox" error when trying to access the HMRC secure mailbox from Sage 50 Payroll. If you are experiencing this issue please reach out HMRC’s Online Services Helpdesk and provide the following information: - Inform them that your are obtaining a ‘Request failed, reason unknown’ error when trying to retrieve notices from the DPS. - Last date a successful retrieval was made, and the first they obtained this error message. This will help HMRC support with the investigations.