Errors seems to be resolved now. Thanks for your patience!

Our internal monitoring shows errors have reduced. However there is still few errors and microsoft is still mitigating the incident: https://status.cloud.microsoft/m365/referrer=serviceStatusRedirect

We expect this to be fully resolved in some time.

We experienced an issue with Microsoft services that impacted mailbox linking in Apollo. During this time, users attempting to connect Outlook or Microsoft 365 mailboxes may have encountered errors, and some customers may also have experienced delays in email sending. This is due to a Microsoft outage and is now being resolved by Microsoft.