Update Notice This is no longer an issue as of August 2022.  ConnectWise has corrected this with  version 2022.1, however there are still known issues with On-Premises installations. Manage release 2021.2 brings a new feature known as “New Calendar Sync for Office 365”, however we are strongly suggesting NOT to enable this feature, until the bugs are worked out. 2021.2 Release notes  do note that this feature is still in Pilot however many have missed

The following only applies to those running ConnectWise Manage On-Premises servers. From ConnectWise KB article “On February 29th, Microsoft enabled the new security defaults policy if a partner has not met Microsoft Partner Security Requirements. For on-premises partners that use Office 365 for their outbound email, we recommend that you install the new ConnectWise SMTP Relay Service which uses Modern Authentication.”   Unfortunately if Streamline IT or other smtp outbound domains are used, this SMTP Relay Service will